Abstract: This invention relates to a taxane derivative represented by the following formula (1): wherein at least one of X and Y represents a group --CO--A--B in which A represents a single bond, an alkylenecarbonyl group or the like and B represents a substituted or unsubstituted piperidino group or the like, the other represents a tert-butoxycarbonyl group or the like, and Z represents a hydrogen atom or a triethylenesilyl group, and also to a drug containing the same.This compound has high solubility in water and also has excellent antitumor activities.

Abstract: Described are novel photochromic six-membered heterocyclic-fused naphthopyran compounds, examples of which are naphthopyran compounds having a substituted or unsubstituted six-membered heterocyclic group fused to one side of the naphtho portion of the naphthopyran and having certain substituents at the position ortho to the oxygen atom of the naphthopyran ring. These compounds may be represented by the following graphic formula: ##STR1## Also described are polymeric organic host materials that contain or that are coated with such compounds or combinations thereof with complementary photochromic compounds, e.g., certain other naphthopyrans, benzopyrans, and spiro(indoline) type compounds.

Abstract: The present invention relates to novel N-substituted amino alcohols, amino acids and acid derivatives thereof in which a substituted alkyl chain forms part of the N-substituent or salts thereof, to methods for their preparation, to compositions containing them, and to their use for the clinical treatment of painful, hyperalgesic and/or inflammatory conditions in which C-fibers play a pathophysiological role by eliciting neurogenic pain or inflammation.

Abstract: The compounds of the present invention are those of structural formula (I) ##STR1## wherein X is oxygen or sulfur. Pharmaceutical compositions and methods of use of the compounds in the treatment of hyperandrogenic conditions are disclosed. In addition, the combination of the compounds with other active agents such as finasteride, minoxidil and retinoic acid or a derivative thereof is disclosed.

Abstract: The present invention relates to a novel chromene compound having favorable photochromic properties, developing a color of a high density, exhibiting a small degree of initial color and permitting the color to quickly fade.

Abstract: The present invention relates to 1,4-disubstituted piperazines of the general formula ##STR1## wherein X, Y, Z, R.sup.1, R.sup.2 and r are as defined in the detailed part of the present description or salts thereof, to methods for their preparation, to compositions containing them, and to their use for the clinical treatment of painful, hyperalgesic and/or inflammatory conditions in which C-fibers play a pathophysiological role by eliciting neurogenic pain or inflammation as well as their use for the treatment of indications caused by or related to the secretion and circulation of insulin antagonizing peptides, e.g. non-insulin-dependent diabetes mellitus (NIDDM) and ageing-associated obesity.

Abstract: Novel aromatic bicyclic amines of formula (I) ##STR1## are useful in treating central nervous system disorders and cardiac arrhythmias and cardiac fibrillation.

Abstract: Described herein are D4 receptor-selective compounds of the general formula: ##STR1## wherein: A and B are independently selected, optionally substituted, unsaturated 5- or 6-membered, homo- or heterocyclic rings;X.sub.1 is selected from CH.sub.2, O, NH, S, C.dbd.O, CH--OH, CH--N(C.sub.1-4 alkyl).sub.2, C.dbd.CHCl, C.dbd.CHCN, N--C.sub.1-4 alkyl, N-acetyl, SO.sub.2 and SO;X.sub.2 - - - is selected from N.dbd., CH.sub.2 --, CH.dbd. and C(O);Y is selected from N and CH;R.sub.1 represents C.sub.1-4 alkyl;n is 0, 1 or 2;q is 1 or 2; andZ is C.sub.5-10 alkyl optionally substituted with OH, halo, C.sub.1-4 alkyl or C.sub.1-4 alkoxy and optionally incorporating a heteroatom selected from O, N and S;and acid addition salts, solvates and hydrates thereof. Their use as ligands for dopamine receptor identification and in a drug screening program, and as pharmaceuticals to treat indications in which D4 receptor stimulation is implicated, such as schizophrenia, is also described.

Abstract: Novel compounds of Formula ##STR1## are disclosed. Also disclosed is a method of inhibiting Ras function and therefore inhibiting the abnormal growth of cells. The method comprises administering a compound of the above formula to a biological system. In particular, the method inhibits the abnormal growth of cells in a mammal such as a human being.

Abstract: Described are novel pentahydrophenanthro?9,10-b!pyrans and tetrahydrocyclopenta?c!-naphtho?1,2-b!pyrans. Also described are polymeric organic host materials that contain or that are coated with such compounds.

Abstract: Disclosed are compounds of the formula: ##STR1## or the pharmaceutically acceptable acid addition salts thereof, wherein: R.sub.1, R.sub.2, R.sub.3, R.sub.4 are the same or different and represent hydrogen, C.sub.1 -C.sub.6 alkyl, halogen, hydroxy, amino, cyano, nitro, trifluoromethyl, trifluoromethoxy, C.sub.1 -C.sub.6 alkoxy, --O.sub.2 CR', --NHCOR', --COR', --SO.sub.m R', where R' is C.sub.1 -C.sub.6 alkyl and wherein m is 0, 1 or 2; orR.sub.1, R.sub.2, R.sub.3, R.sub.4 independently represent --CONR'R", or --NR'R" where R' and R" independently represent hydrogen or C.sub.1 -C.sub.6 alkyl;R.sub.5 is hydrogen or C.sub.1 -C.sub.6 alkyl; andR represents an aminoalkyl group, which compounds are useful in the treatment of affective disorders such as schizophrenia, depression, Alzheimer's disease, movement disorders such as Parkinsonism and dystonia, and other disorders which respond to dopaminergic blockade such as substance abuse and obsessive compulsive disorders.

Abstract: Disclosed are compounds of the formula: ##STR1## or the pharmaceutically acceptable acid addition salts thereof, wherein: R.sub.1, R.sub.2, R.sub.3, R.sub.4 are the same or different and represent hydrogen, C.sub.1 -C.sub.6 alkyl, halogen, hydroxy, amino, cyano, nitro, trifluoromethyl, trifluoromethoxy, C.sub.1 -C.sub.6 alkoxy, --O.sub.2 CR', --NHCOR', --COR', --SO.sub.m R', where R' is C.sub.1 -C.sub.6 alkyl and wherein m is 0, 1, or 2; orR.sub.1, R.sub.2, R.sub.3, R.sub.4 independently represent --CONR'.sub.m, or --NR'.sub.m where m is 0, 1 or 2 and R' is hydrogen or C.sub.1 -C.sub.6 alkyl;R.sub.5 is hydrogen or C.sub.1 -C.sub.6 alkyl; andR represents an aminoalkyl group,which compounds are useful in the treatment of affective disorders such as schizophrenia, depression, Alzheimer's disease, movement disorders such as Parkinsonism and dystonia, and other disorders which respond to dopaminergic blockage such as substance abuse and obsessive compulsive disorders.

Abstract: A naphthopyran compound represented by the formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, and R.sub.10 are each selected from the group consisting essentially of hydrogen, a stable organic radical, a heterocyclic group, a halogen, a nitrogen-substituted group, and a nitrogen-substituted ring compound and wherein A is a substituted divalent aromatic radical that includes substituents selected from the group consisting essentially of hydrogen and the stable organic radical.

Abstract: Described are novel reversible photochromic 2H-naphtho[1,2-b] pyran compounds, examples of which are compounds having certain substituents at the number 5 carbon atom of the naphtho-portion of the naphthopyran and at the 2-position of the pyran ring. Certain substituents may also be present at the number 6, 7, 8, 9 or 10 carbon atoms of the naphtho portion of the naphthopyran. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Abstract: Described are novel reversible photochromic 2H-naphtho[1,2-b]pyran compounds, examples of which are compounds having certain substituents at the number 5 carbon atom of the naphtho-portion of the naphthopyran and at the 2-position of the pyran ring. Certain substituents may also be present at the number 6, 7, 8, 9 or 10 carbon atoms of the naphtho portion of the naphthopyran. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Abstract: Described are novel reversible photochromic 2H-naphtho[1,2-b]pyran compounds, examples of which are compounds having certain substituents at the number 5 carbon atom of the naphtho portion of the naphthopyran and at the 2-position of the pyran ring. Certain substituents may also be present at the number 6, 7, 8, 9 or 10 carbon atoms of the naphtho portion of the naphthopyran. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Abstract: Described are novel reversible photochromic 2H-naphtho[1,2-b]pyran compounds, examples of which are compounds fused on the naphtho-portion of the naphthopyran ring with an indeno group or certain heterocyclic substituents. Certain substituents are also present at the 2 and 5 positions and sometimes at the 6 position of the naphthopyran ring. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Abstract: Described are novel reversible photochromic 2H-naphtho[1,2-b]pyran compounds, examples of which are compounds having certain substituents at the 5 and 6-positions of the naphtho portion of the naphthopyran and at the 2-position of the pyran ring, e.g., 2,2-bis(4-methoxy phenyl)-5-methoxycarbonyl-6-morpholino-2H-naphtho[1,2-b]pyran. Certain substituents may also be present at the number 7, 8, 9 or 10 carbon atoms of the naphtho portion of the naphthopyran. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Abstract: A naphthopyran compound represented by the formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, and R.sub.10 are each selected from the group consisting essentially of hydrogen, a stable organic radical, a heterocyclic group, a halogen, a nitrogen-substituted group, and a nitrogen-substituted ring compound and wherein A is a substituted divalent aromatic radical that includes substituents selected from the group consisting essentially of hydrogen and the stable organic radical.

Abstract: A 4-desoxy-4-epipodophyllotoxin derivative of the following formula ##STR1## wherein R and R.sub.1 are as defined in the specification or a pharmaceutically acceptable salt thereof as well as an antitumor composition comprising such derivative or salt as an active ingredient.

Abstract: Photochromic products belonging to the group of chromenes having general formula (I): ##STR1##

Abstract: A 4-desoxy-4-epipodophyllotoxin derivative of the following formula ##STR1## wherein R and R.sub.1 are as defined in the specification or a pharmaceutically acceptable salt thereof as well as an antitumor composition comprising such derivative or salt as an active ingredient.

Abstract: Analgesic compounds of the formula (I); ##STR1## in which, R.sup.1 and R.sup.2 each represents hydrogen or C.sub.1 -C.sub.6 alkyl, or R.sup.1 and R.sup.2 together with the nitrogen atom to which they are attached form a heterocycle; E represents oxygen or an imino group optionally substituted with C.sub.1 -C.sub.6 alkyl or aralkyl; ring A is an aryl or heteroaryl ring, optionally substituted; R.sup.3 is hydrogen or C.sub.1 -C.sub.6 alkyl and R.sup.4 is hydrogen or R.sup.3 and R.sup.4 together represent a group of formula (IV):--(CR.sup.a R.sup.a).sub.m --C(.dbd.Y)-- (IV)wherein R.sup.a and R.sup.a is C.sub.1 -C.sub.6 alkyl or hydrogen, up to a maximum of 3 alkyl groups, m is 1, 2, or 3, and Y is two hydrogens or oxygen; provided that when E represents a methylene group, then R.sup.3 is a C.sub.1 -C.sub.6 alkyl group or R.sup.3 and R.sup.4 together represent a group of the formula (IV).

Abstract: Benzopyran derivatives which have an inhibitory effect on the Maillard reaction as well as an antioxidizing effect are described herein. These derivatives may be utilized in the treatment and/or prevention of diabetic complications such as, for example, coronary heart disease, peripheral circulatory insufficiency or failure, cerebrovascular hindrance, neurogenous diabetes, nephropathy, arteriosclerosis, arthrosclerosis, cataracts and retinopathy. Further, the derivatives may also be used in the treatment and/or prevention of diseases induced by aging and in the treatment and/or prevention of diseases caused by the formation of peroxidized fat.

Abstract: Piperidine and piperazine derivatives of formula I ##STR1## wherein R.sup.1 and R.sup.2 are H or A,R.sup.3, R.sup.4 and R.sup.5 are each independently H, Hal, OH, OA, OAc, NO.sub.2, NH.sub.2, NHAc, NHSO.sub.2 A or CN, orR.sup.3 and R.sup.4 together are --O--(CH.sub.2).sub.m --O--,n is 0, 1 or 2X is O or CH.sub.2, if n=0 or 2, or CH.sub.2, NH, NA or NAc, if n=1,Y is CH or N,m is 1 or 2,Hal is F, Cl, Br or I,A is C.sub.1-6 -alkyl,Ac is C.sub.1-8 -alkanoyl C.sub.1-10 -aralkanoyl or C.sub.7-11 -aroyl,and their physiologically acceptable salts show antiarrhythmic effects.

Abstract: The present invention concerns water-soluble amino acid derivatives of paclitaxel, their use as antitumor agents, and pharmaceutical compositions containg the compounds.

Abstract: This invention relates to a process for the preparation of a 6,7-diacyl-7-deacetylforskolin derivative represented by the general formula: ##STR1## wherein R.sup.1 and R.sup.2 each stands for an acyl group and R.sup.3 stands for an aliphatic group having 2 to 3 carbon atoms, which comprises eliminating the acyl group at position 1 in a 1,6,7-triacyl-7-deacetylforskolin derivative represented by the general formula: ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above, by solvolysis. The compound of the formula (I) is expected as medicine.

Abstract: Described are novel reversible photochromic 3H-naphtho[2,1-b]pyran compounds, of the following graphic formula: ##STR1## wherein R.sub.1 is hydrogen or alkyl, R.sub.2 is hydrogen or preferably a carboalkoxy group and R.sub.3 is hydrogen or preferably an alkyl group, provided that either R.sub.1 or R.sub.2 is hydrogen, and B and B' are the aryl groups phenyl or naphthyl, a heterocyclic aromatic group or together form a spiro adamantylene group. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(oxazine) type compounds, are also described.

Abstract: Described are novel reversible photochromic naphthopyran compounds, examples of which are compounds having certain substituents at the number 5 and 6 carbon atoms of the naphtho portion of the naphthopyran and at the 2-position of the pyran ring. Certain substituents may also be present at the number 7, 8, 9 or 10 carbon atoms of the naphtho portion of the naphthopyran. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Abstract: Compounds of the formula ##STR1## wherein ring A, ring B, ring D, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6,R.sup.11, R.sup.12, R.sup.13, E, G, X and P are as defined below. The compounds of formula I are cholinesterase inhibitors and are useful in enhancing memory in patients suffering from dementia and Alzheimer's disease.

Abstract: A 2-Acylaminothiazole of formula: ##STR1## in which R.sub.1 is H, an alkyl or a substituted alkyl; R.sub.IV is a cycloalkyl, an aromatic group such as phenyl or a heterocyclic group which are unsubstituted or substituted; R.sub.V is a substituted alkyl, a substituted carboxy such as an ester or an amide; or R.sub.IV and R.sub.V together represent a phenoxyalkylene group which may be substituted on the phenyl; and Z is a heterocyclic e.g. indolyl group; or a salt of compound (I).

Abstract: A benzodifuranone compounds of the formula, ##STR1## wherein R.sup.1 and R.sup.2 are each independently a naphthyl group or an unsubstituted or substituted phenyl group, which is useful for dyeing or printing hydrophobic fiber materials, is prepared in high purity and high yield by allowing benzofuran compounds of the formula, ##STR2## wherein R.sup.1 is as defined above, to react with acetonitrile compounds of the formula, ##STR3## wherein R.sup.2 is as defined above, and then carrying out an oxidation reaction to give the benzodifuranone compound.

Abstract: Taxane derivatives of the formula ##STR1## wherein R.sub.1 is butenyl,R.sub.3 is phenyl,T.sub.1 is hydrogen, hydroxyl protecting group, or --COT.sub.2,T.sub.2 is H, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl or monocylic aryl,Ac is acetyl, andE.sub.1 and E.sub.2 are independently selected from hydrogen and functional groups which increase the water solubility of the taxane derivative are useful as antitumor agents.

Abstract: Taxane derivatives of the formula ##STR1## wherein R.sub.1 is cyclohexyl,R.sub.3 is phenyl,T.sub.1 is hydrogen, hydroxyl protecting group, or --COT.sub.2,T.sub.2 is H, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl or monocylic aryl,Ac is acetyl, andE.sub.1 and E.sub.2 are independently selected from hydrogen and functional groups which increase the water solubility of the taxane derivative are useful as antitumor agents.

Abstract: Taxane derivatives of the formula ##STR1## wherein R.sub.1 is phenyl or p-nitrophenyl,R.sub.3 is furyl or thienyl,T.sub.1 is hydrogen, hydroxyl protecting group, or --COT.sub.2,T.sub.2 is H, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl or monocylic aryl,Ac is acetyl, andE.sub.1 and E.sub.2 are independently selected from hydrogen and functional groups which increase the water solubility of the taxane derivative are useful as antitumor agents.

Abstract: Process for the preparation of 6-acyl-, 7-acyl- or 6,7-diacyl analogues of forskolin of the general formula ##STR1##

Abstract: The present invention relates to labdane-derivatives of the formula ##STR1## a process for their preparation and the use of these substances as medicaments, preferably as medicaments having a positive ionotropic effect, an effect of lowering intraocular pressure and lowing blood pressure.

Abstract: Process for the manufacture of 6.beta.

Abstract: Novel aminoalkylthiodibenzoxepins, physiologically tolerable acid addition salts thereof, a method of preparing same, pharmaceutical and veterinary preparations including same and methods of treating by administering same are disclosed. These compounds are useful as analgesic, antidepressant and anticonvulsant agents. A process for selectively reducing olefins by alkaline earth metals in loweralkanols is also disclosed.

Abstract: Labdanes of the formula ##STR1## a process for their manufacture, pharmaceutical preparations containing an effective amount of these compounds and their use for the manufacture of a pharmaceutical preparation for treatment of cardiovascular diseases and high intraocular pressure.

Abstract: Compounds of formula (I): ##STR1## wherein R.sup.1 and R.sup.2 is each --R.sup.5, --CH.dbd.CH--R.sup.5 or --C.tbd.C--R.sup.5, wherein R.sup.5 is optionally substituted aryl or aromatic heterocyclic; R.sup.3 is hydrogen, alkyl, cyano or --R.sup.5 ; X is oxygen or sulfur; A is 1,4-piperazin-1,4-diyl or a 1,4-homopiperazin-1,4-diyl; B' is alkylene, carbonyl, thiocarbonyl, sulfinyl or sulfonyl; and R.sup.4 is optionally substituted phenyl and pharmaceutically acceptable salts thereof have valuable PAF antagonist activity, and may be prepared by reacting a compound containing the piperazine or homopiperazine part of the molecular with a compound containing the other part of the molecule.

Abstract: Bivalent ligand compounds synthesized from a tether composition joining two heterocyclic groups comprising furochromones, furobenzoxazinones, and benzobisdifurans. These compounds show pharmacological activity in blocking ACAT enzymes which are major regulators of cholesterol metabolism. The compounds also show activity in lowering plasma triglycerides and elevating HDL cholesterol. They are useful in the prevention or treatment of the constriction or obstruction of arterial vessels, atherosclerosis, hyperlipidemia, hypertriglyceridemia, chylomicronemia, and pancreatitis.

Abstract: A dibenz[b,e]oxepin derivative represented by the formula (I) ##STR1## wherein R.sup.1 and R.sup.2 are each hydrogen, halogen, lower alkyl or alkoxy; one of R.sup.3 and R.sup.4 is lower alkoxy, and other is a group represented by the formula (II) ##STR2## wherein R.sup.5 is hydrogen or lower alkyl, A is hydroxyl, --O(CH.sub.2).sub.m --R.sup.6 (wherein m is an integer of 1-6, R.sup.6 is hydrogen, lower alkyl or alkoxy, cycloamino, or lower alkoxycarbonyl), cycloamino, di-lower alkylamino or --NH(CH.sub.2).sub.n --R.sup.7 (wherein n is an integer of 0-3, R.sup.7 is hydrogen, hydroxyl, phenyl, thiazole or cycloamino).

Abstract: A renin inhibiting compound of the formula ##STR1## wherein X is N, O or CH; R.sub.1 is absent or a functional group; A and L are independently selected from absent, C.dbd.O, SO.sub.2 and CH.sub.2 ; D is C.dbd.O, SO.sub.2 or CH.sub.2 ; Y is N or CH; R.sub.2 is hydrogen, loweralkyl or substituted alkyl; Z is a functional group; R.sub.3 is loweralkyl or substituted alkyl; n is 0 or 1; and T is a mimic of the Leu-Val cleavage site of angiotensinogen; or a pharmaceutically acceptable salt, ester or prodrug thereof.

Abstract: Novel tricyclic compounds having a TXA.sub.2 antagonizing activity represented by formula (I): ##STR1## possess a potent antagonizing action against thromboxane A.sub.2 and also an antiallergic and/or antihistaminic acitvity, and are expected to have preventive and therapeutic effects on ischemic diseases, cerebro-vascular diseases, etc.

Abstract: Novel aminoalkylthiodibenzoxepins, physiologically tolerable acid addition salts thereof, a method of preparing same, pharmaceutical and veterinary preparations including same and methods of treating by administering same are disclosed. These compounds are useful as analgesic, antidepressant and anticonvulsant agents. A process for selectively reducing olefins by alkaline earth metals in loweralkanols is also disclosed.

Abstract: The present invention is directed to a fluorescence polarization assay for phencyclidine and phencyclidine derivatives, to the various components needed for preparing and carrying out such an assay, and to methods of making these components. Specifically, tracers, immunogens and antibodies are disclosed, as well as methods for making them. The tracers and the immunogens are made from substituted phencyclidine compounds. A fluorescein moiety is included in the tracer, while a poly(amino acid) forms a part of the immunogen. The assay is conducted by measuring the degree of polarization retention of plane polarized light that has been passed through a sample containing antiserum and tracer.

Abstract: Novel dibenz[b,e]oxepin derivatives are employed in the treatment and control of allergic conditions such as allergic asthma and also employed in the treatment of inflammation.

Abstract: This invention relates to a compound of formula I ##STR1## or a pharmaceutically acceptable salt thereof, in which R.sup.2 is a radical of the formula ##STR2## in which R.sup.a and R.sup.b are independently hydrogen or C.sub.1-6 alkyl, said C.sub.1-6 alkyl being optionally substituted with hydroxy, phosphono, phosphonooxy, carboxy or di(C.sub.1-6 alkyl) amino; or NR.sup.a R.sup.b together represents a radical of the formula ##STR3## in which y is one to three, and R.sup.a is as defined above; R.sup.p and R.sup.r are independently same or different C.sub.1-6 alkyl;R.sup.1 is hydrogen or a radical Z of the formula ##STR4## in which Q is --(CH.sub.2).sub.f --, optionally substituted with one to six same or different C.sub.1-6 alkyl or C.sub.3-6 cycloalkyl, or a carbon atom of said --(CH.sub.2).sub.f -- radical may also be a part of C.sub.3-6 cycloalkylidene;R.sup.3 and R.sup.4 are independently hydrogen or C.sub.1-6 alkyl, or R.sup.3 and R.sup.