摘要:
A process for preparing an optically active (2S,3S)-allophenylnorstatin derivative (I) is disclosed, comprising asymmetrically hydrogenating a 4-phenyl-2-halogeno-3-oxobutyric ester (III) in the presence of a ruthenium-phosphine complex to obtain a 4-phenyl-(2S)-halogeno-(3R)-hydroxybutyric ester (IV), epoxidizing the ester (IV) in the presence of a base to obtain a 4-phenyl-(2S,3R)-epoxybutyric ester (V), reacting the ester (V) with a tri(lower alkyl)silylazide or a (lower alkyl)diarylsilylazide in the presence of a Lewis to obtain a (3S)-azido-4-phenyl-(2S)-trisubstituted silyloxybutyric ester (VI), hydrogenolyzing the ester (VI) into a (2S,3S)-allophenylnorstatin derivative (VII), protecting the amino group of the compound (VII), and, if desired, hydrolyzing the compound before or after the amino group protection. Compounds (I) can be obtained at high optical purity safely and in good yield.
摘要:
Disclosed herein is a process for producing a (2S,5S)-2,5-diamino-1,6-diphenyl-3-hexanone derivative represented by the formula (1): ##STR1## wherein R.sup.1 means a lower alkylcarbonyl group, a halogen-substituted lower alkylcarbonyl group, an arylcarbonyl group or a lower alkoxycarbonyl group, and R.sup.2 and R.sup.3 are identical with or different from each other and denote individually an aryl group or an alkoxy-substituted aryl group, which comprises subjecting a (2S)-2,5-diamino-1,6-diphenyl-4-hexen-3-one derivative represented by the formula (2): ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 have the same meaning as defined above, to a hydrogenation reaction in the presence of a transition metal-containing catalyst.
摘要:
A novel chiral unsymmetric diphosphine compound of formula (I): ##STR1## wherein Ar.sup.1 and Ar.sup.2, which are different from each other, each represent a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a pyridyl group, a quinolyl group, an isoquinolyl group, a furfuryl group, a benzofurfuryl group, a thienyl group, or a benzothienyl group, and a transition metal complex containing the diphosphine compound as a ligand. The complex catalyzes various asymmetric synthesis reactions, e.g., asymmetric hydrogenation or asymmetric hydrosilylation, exhibiting excellent performance in selectivity, conversion and catalytic activity, to provide a product of desired absolute configuration at high optical purity and in high yield.
摘要:
Disclosed herein is a process for producing a (2S,5S)-2,5-diamino-1,6-diphenyl-3-hexanone derivative represented by the formula (1): ##STR1## wherein R.sup.1 means a lower alkylcarbonyl group, a halogen-substituted lower alkylcarbonyl group, an arylcarbonyl group or a lower alkoxycarbonyl group, and R.sup.2 and R.sup.3 are identical with or different from each other and denote individually an aryl group or an alkoxy-substituted aryl group, which comprises subjecting a (2S)-2,5-diamino-1,6-diphenyl-4-hexen-3-one derivative represented by the formula (2): ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 have the same meaning as defined above, to a hydrogenation reaction in the presence of a transition metal-containing catalyst.
摘要:
Purine derivatives of the formula ##STR1## wherein R is C.sub.1 -C.sub.6 alkyl and R.sub.1 is ##STR2## and their pharmaceutically acceptable acid addition salts are non-adrenergic bronchodilators.
摘要:
Adenine derivatives with 2-alkylthio and 9-(2-cyclohexenyl or cyclohexyl) substituents having non-adrenergic bronchodilating properties and use in the treatment or prophylaxis of broncho-constriction in mammals are disclosed.
摘要:
Purine derivatives of the formula ##STR1## wherein R is C.sub.1 -C.sub.6 alkyl and R.sub.1 is ##STR2## OR ##STR3## AND THEIR PHARMACEUTICALLY ACCEPTABLE ACID ADDITION SALTS ARE NON-ADRENERGIC BRONCHODILATORS.
摘要:
A keratin fiber strengthening agent comprising 0.001 to 20% by weight of at least one (2S,3R)-2-acylaminoalkane-1,3-diol represented by formula (I): wherein R1 represents a straight-chain alkyl group having 9 to 17 carbon atoms; and R2 represents an acyl group having 2 to 24 carbon atoms which may contain at least one hydroxy group or unsaturated bond is disclosed. A method for improving physical properties, such as breaking strength, of keratin fiber such as hair comprising applying the keratin fiber strengthening agent to keratin fiber by adhesion, coating or impregnation is also disclosed.
摘要:
The present invention concerns neutral sugar derivatives of pradimicins, their use as antifungal agents, methods for their preparation, and intermediates for their synthesis.