摘要:
Provided are a novel ammonium (3R,5S)-3,5,6-trihydroxyhexanoate derivative represented by the following formula (I): wherein R1 represents a benzyl group which may have a substituent, a triphenylmethyl group which may have a substituent, an organosilyl group or a C1-5 acyl group; and A means a specific amine; and a preparation process of the derivative.
摘要:
A process for preparing optically active 4-methyl-2-oxetanone which comprises asymmetrically hydrogenating 4-methylene-2-oxetanone in the presence of a ruthenium-optically active phosphine complex. Optically active 4-methyl-2-oxetanone can easily and economically be obtained at high optical purity.
摘要:
A biodegradable optically active copolymer is disclosed, which is represented by the general formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each represents a hydrogen atom or a methyl group; m and n each represents a natural number wherein the sum thereof gives 10 to 5,000; and C* represents an asymmetric carbon atom, and a process for producing the copolymer by ring-opening copolymerization of optically active .beta.-butyrolactone with a cyclic carbonate in the presence of catalyst. The biodegradable optically active copolymer of the present invention provides excellent biodegradability (enzyme degradability) and hydrolyzability.
摘要翻译:公开了一种可生物降解的光学活性共聚物,其由通式(I)表示:其中R 1,R 2,R 3和R 4各自表示氢原子或甲基; m和n各自表示其总和为10至5,000的自然数; C *表示不对称碳原子,以及在催化剂存在下通过光学活性β-丁内酯与环状碳酸酯开环共聚制备共聚物的方法。 本发明的生物降解性光学活性共聚物提供优异的生物降解性(酶降解性)和水解性。
摘要:
A novel phosphine compound usable as a catalyst in various asymmetric synthetic reactions is disclosed. The compound is a 2,2'-bis(diarylphosphino)-6,6'-bis(trifluoromethyl)-1,1'-biphenyl of (1): ##STR1## where R is a phenyl group or a phenyl group substituted by lower alkyl group, lower alkoxy group, halogen atom, or lower haloalkyl group.
摘要:
The object of the invention is to provides a process in which a high-molecular-weight &bgr;-butyrolactone homopolymer or copolymer being biodegradable, absorbable into the living body, useful as a functional polymeric material and superior in physical characteristics is produced with high yield and good productivity. This object is solved by a process for producing the homopolymer or copolymer of the invention, which comprises ring-opening polymerization of sole &bgr;-butyrolactone subjected previously to acid removal and dehydration treatment, or of said &bgr;-butyrolactone with other lactones, in the presence of a tin compound represented by the following formula (1) and/or formula (2): wherein R1 and R2 and R4 to R7 independently represent an alkyl group containing 1 to 12 carbon atoms which may have a branched chain, or a cycloalkyl group containing 5 to 7 carbon atoms, or a phenyl or naphthyl group which may have a substituent group, R3 represents an alkylene group containing 2 to 12 carbon atoms which may have a substituent group, a cyclopentane-1,2-ylene group or a cyclohexane-1,2-ylene group, and n is an integer of 1 to 10.