摘要:
Disclosed is a process for preparing an optically active oxazolidinone derivative comprising allowing hydrazine to react on an optically active ester having a hydroxyl group at the 3-position which is represented by formula (II): wherein R1 represents a lower alkyl group having 1 to 4 carbon atoms, a phenyl group, a methoxymethyl group, a benzyloxymethyl group, a benzyloxycarbonylaminomethyl group which may have a substituent or substituents on the benzene ring thereof, an acylaminomethyl group having 3 to 10 carbon atoms, or an alkyloxycarbonylaminomethyl group having 3 to 6 carbon atoms; R2 and R3, which may be the same or different, each represent a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, a phenyl group, an acetylaminomethyl group, a benzoylaminomethyl group, or a benzyl group; and * indicates an asymmetric carbon atom, and subjecting the resulting hydrazide to Curtius rearrangement.
摘要翻译:公开了一种制备光学活性恶唑烷酮衍生物的方法,其包括使肼在由式(II)表示的3-位具有羟基的光学活性酯上反应:其中R1表示具有1-4个碳原子的低级烷基 碳原子,苯基,甲氧基甲基,苄氧基甲基,苯环上可以具有取代基的苄氧羰基氨基甲基,碳原子数3〜10的酰氨基甲基或碳原子数3〜6的烷氧基羰基氨基甲基 原子 R 2和R 3可以相同或不同,分别表示氢原子,碳原子数1〜4的低级烷基,苯基,乙酰氨基甲基,苯甲酰基氨基甲基或苄基。 和*表示不对称碳原子,并将所得酰肼进行柯氏重排。
摘要:
An optically active compound represented by formula (I): wherein A represents ##STR1## wherein R.sup.2 represents an alkyl group having from 8 to 12 carbon atoms; R.sup.1 represents a straight chain alkyl group having from 2 to 5 carbon atoms; X represents a fluorine atom or a methyl group; n represents 1 or 2; m represents an integer of from 0 to 3; and C* represents an asymmetric carbon atom, and a liquid crystal composition containing the same are disclosed. The compound exhibits large spontaneous polarization and low viscosity and, when added to an achiral base liquid crystal composition, induces a chiral nematic phase in which the helical pitch has small temperature dependence.
摘要翻译:由式(I)表示的光学活性化合物:其中A表示其中R2表示具有8至12个碳原子的烷基; R1表示具有2至5个碳原子的直链烷基; X表示氟原子或甲基; n表示1或2; m表示0〜3的整数, C *表示不对称碳原子,含有该碳原子的液晶组合物。 该化合物表现出大的自发极化和低粘度,并且当添加到非手性基底液晶组合物时,诱导手性向列相,其中螺旋间距具有较小的温度依赖性。
摘要:
A process for producing cyclohexylazetidinone expressed by the formula(IV) comprises condensing the magnesium enolate compound expressed by the formula (II) with acyloxyazetidinone expressed by the formula (III), wherein Me is a methyl group; R.sup.1 is a hydroxyl-protecting group, R.sup.2 is an acyl group, and X is a halogen atom. ##STR1##
摘要:
A fluorine-containing optically active compound represented by formula (I): ##STR1## wherein R.sub.1 represents a straight chain alkyl or alkoxy group having from 6 to 14 carbon atoms or a 4-alkylphenyl or 4-alkoxyphenyl group having from 8 to 12 carbon atoms; R.sub.2 represents a straight chain alkyl group having from 1 to 8 carbon atoms; C.sup.* represents an asymmetric carbon atoms; and X represents a hydrogen atom or a fluorine atom, provided that X represents a fluorine atom when R.sub.1 contains a phenyl group, and a liquid crystal composition containing the same are disclosed. The compound (I) has large spontaneous polarization and low viscosity to achieve a fast response time. In the N.sup.* phase of the compound (I), the helical pitch has small temperature dependence.
摘要翻译:由式(I)表示的含氟光学活性化合物:(*化学结构*)(I)其中R1表示具有6至14个碳原子的直链烷基或烷氧基或4-烷基苯基或4-烷氧基苯基 具有8至12个碳原子; R 2表示具有1至8个碳原子的直链烷基; C *表示不对称碳原子; 并且X表示氢原子或氟原子,条件是当R 1包含苯基时,X表示氟原子,并且公开了含有该基团的液晶组合物。 化合物(I)具有大的自发极化和低粘度以实现快速响应时间。 在化合物(I)的N *相中,螺旋间距具有较小的温度依赖性。
摘要:
A process for preparing optically active 4-hydroxy-2-pyrrolidone comprising asymmetrically hydrogenating an N-substituted-4-amino-3-oxobutanoic ester represented by formula (I): ##STR1## wherein R.sup.1 represents a benzyloxycarbonyl group, the benzene ring of which may be substituted; and R.sup.2 represents a lower alkyl group having 1 to 4 carbon atoms, in the presence of a ruthenium-optically active phosphine complex as a catalyst to obtain an optically active N-substituted-4-amino-3-hydroxybutanoic ester, deblocking, and cyclizing the ester. A series of the reactions can be carried out in one pot. Optically active 4-hydroxy-2-pyrrolidone is obtained in high yield with high optical purity, and is useful in the synthesis of carbapenem antibiotics
摘要:
A liquid crystal compound represented by formula: ##STR1## wherein R.sub.1 represents a straight chain alkyl group having from 4 to 18 carbon atoms; R.sub.2 represents a straight chain alkyl group having from 2 to 6 carbon atoms or a branched alkyl group having from 3 to 6 atoms and having a methyl group as a side chain; and m and n each represents 1 or 2, is disclosed.The liquid crystal compound of formula (I) is optically and electrically stable and exhibits fast electro-optical switching in image display.
摘要:
T-butyl (R)-(-)-4-cyano-3-hydroxybutyrate having an optical purity of 99%ee or higher and a process for producing the same are disclosed, the process comprising cyanogenation of a t-butyl (S)-(-)-4-halogeno-3-hydroxybutyrate obtained by enantioselective hydrogenation of a t-butyl 4-halogenoacetoacetate. Recrystallization of the resulting crude product gives the optically active compound with high optical purity.
摘要:
A (3R,5S)-3,5,6-trihydroxyhexanoic acid derivative and a process of producing the (3R,5S)-3,5,6-trihydroxyhexanoic acid derivative which comprises the step of enantioselectively hydrogenating an (S)-5,6-dihydroxy-3-oxohexanoic acid derivative with a specific ruthenium-optically active phosphine complex represented as a catalyst are disclosed. The (3R,5S)-3,5,6-trihydroxyhexanoic acid derivative which is a useful compound capable of being easily converted into a lactone moiety, which is the active part of an inhibitor on HMG-CoA reductase, can be easily and efficiently obtained under a mild reaction condition with a high selectivity for the syn-diol form.
摘要:
Disclosed herein is a process for producing a .gamma.-hydroxyketone (2), which comprises asymmetrically hydrogenating a .gamma.-diketone (1) in the presence of a ruthenium-optically active phosphine complex as a catalyst ##STR1## wherein R.sup.1 and R.sup.2 mean individually an alkyl or phenyl group which may have a substituent group. According to the invention, optically active .gamma.-hydroxyketones useful in synthesizing optically active moiety in, biodegradable polymers, perfumes, intermediates for synthesizing medicines and the like can be efficiently prepared.
摘要:
A liquid crystal compound represented by formula: ##STR1## wherein R.sub.1 represents a straight chain alkyl group having from 4 to 18 carbon atoms; R.sub.2 represents a straight chain alkyl group having from 2 to 6 carbon atoms or a branched alkyl group having from 3 to 6 atoms and having a methyl group as a side chain; and m and n each represents 1 or 2, is disclosed.The liquid crystal compound of formula (I) is optically and electrically stable and exhibits fast electro-optical switching in image display.