1-烷（苯）氧基-3-（3，4-亚甲基二氧）苯基-2-丙醇的合成与生物活性研究

黄樟素氧化物与烷氧基钠和苯氧基钠反应，区域选择性地开环加成，生成1-烷 （苯）氧基-3-（3，4-亚甲基二氧）苯基-2-丙醇。该系列化合物具有诱导细胞凋 亡与分化的生物活性。     

Enantioselective oxidation of (RS)-2-phenyl-1-propanol to (S)-2-phenylpropanoic acid with Gluconobacter oxydans: simplex optimization of the biotransformation

The microbial oxidation of racemic 2-phenyl-1-propanol by Gluconobacter oxydans DSM 50049 was investigated. Whole bacterial cells were used to produce (S)-(+)-2-phenylpropanoic acid with high enantiomeric excess (E>200). A simplex sequential method was employed as an experimental design to guide the optimization process. Temperature of 26–28°C, pH 6.0–6.2, substrate concentration of 20–25 mM and agitation of 150 rpm have been found the best conditions to achieve the highest reaction rates and enantioselectivities.     

Synthesis of 3-fluoro-2-(trinitromethyl)-1-propanol

Conclusions 3-Fluoro-2-(trinltromethyl)-1-propanol nitrate, the acid hydrolysis of which resulted in 3-fluoro-2-(trinitromethyl)-1-propanol, was obtained by the direct fluorination of 2,4-bis(trinitromethyl)-4-mercuri-1,7-heptanediol.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1650–1651, July, 1972.     

Enantioselective hydrolysis of (RS)-2-fluoroarylacetonitriles using nitrilase from Arabidopsis thaliana

The enzymatic resolution of 2-fluoroarylacetonitriles (RS)-3 using nitrilase from the plant Arabidopsis thaliana is described. Racemic 2-fluoronitriles 3 are easily accessible from O-silylated aromatic cyanohydrins 2 by reaction with DAST. The nitriles (RS)-3 were hydrolysed with the nitrilase as a catalyst, not to the expected 2-fluoroarylacetic acids but to the corresponding (R)-2-fluoroarylacetamides (R)-5 as the main products. After optimization of reaction conditions (pH 9, 7°C), the enantiomeric excesses of (R)-5a,c and f (R=H, 3-Me, 3-OMe) could be improved to >99% by one recrystallization. The acid catalysed hydrolysis of (R)-5a,5c and 5f afforded the corresponding (R)-2-fluoroarylacetic acids (R)-4a,4c and 4f without racemization.     

通过氧杂Pictet-Spengler反应从1-烷(苯)氧基-3-(3,4-亚甲基二氧)苯基-2-丙醇合成异色满衍生物

通过氧杂Pictet-Spengler反应从1-烷氧基-3-(3,4-亚甲基二氧)苯基-2-丙醇及1-苯氧基-3-(3,4-亚甲基二氧)苯基-2-丙醇合成一系列异色满衍生物,即3-烷(苯)氧基-1-苯基-6,7-亚甲基二氧异色满和3-烷(苯)氧基-1,1-二甲基-6,7-亚甲基二氧异色满,收率为50%～90%.     

手性氨基醇（R）－2－氨基－1，1－二苯基－3－（2－萘基）－1－丙醇：制备及其对前手性酮硼烷还原的对映选择性催化作用

用丙二酸酯法合成了Ｎ－乙酰基－３－（２－萘基）－ＤＬ－α－丙氨酸乙酯３．３经酶法拆分，得光学活性的Ｄ－３，后者经盐酸水解、酯化后再与苯基溴化镁作用，制得标题化合物６。在０．５ｍｍｏｌ６存在下，用过量硼烷对一系列前手性酮还原，得到了相应的光学活性二级醇。对映体过量（ｅ．ｅ值）５７．０～１００％。     

Resolution of 2-bromo-o-tolyl-carboxylic acid by transesterification using lipases from Rhizomucor miehei and Pseudomonas cepacia

Several lipases were screened for their ability to catalyze the enantioselective transesterification of 2-bromo-o-tolyl acetic acid. Amongst the preparations tested, the lipases from Rhizomucor miehei and Pseudomonas cepacia were selected. The best enantioselectivity was obtained with Rhizomucor miehei lipase immobilized on polypropylene (E=11.3), which was more stereoselective than the free form. Hydrophobic solvents with log P higher than 2.5 were the most suitable giving the highest E-values. In addition, factors such as the water activity and the reaction temperature had little effect on the resolution of the racemic mixture. The selectivity of the enzymes with respect to the substrate was also only weakly affected by the structure of the leaving alcohol except in the case of the iso-propyl group, which causes high steric hindrance. Operating conditions under reduced pressure were defined to resolve the racemic mixture with immobilized Rhizomucor miehei lipase.     

(S)-2-Amino-3-(2,5-dimethylphenyl)-1,1-diphenyl-1-propanol: Synthesis and Application in Enantioselective Reduction of Prochiral Ketones

The title chiral amino alcohol 6 was prepared from (s)-3-(2,5-dimethylphenyl)-alanine methyl ester hydrochloride by its reaction with phenyl magnesium bromide. In the presence of 2 mol% of 6, the borane reduction of prochiral ketones gave optically active secondary alcohols in high yields with the ee's ranged from 40.5 to 100%.     

Enantioselective MSPV reduction of ketimines using 2-propanol and (BINOL)Al(III)

[reaction: see text] A highly enantioselective Meerwein-Schmidt-Ponndorf-Verley (MSPV) reduction of N-phosphinoyl ketimines by (BINOL)Al(III)/2-propanol is reported. Yields ranging between 79 and 85% with high enantiomeric excesses (93-98%) are observed for a wide range of structurally diverse ketimines. A [2.0.4] bicyclic chelation model is proposed to account for this high selectivity.     

Transformation of trans-4-aryl-3-chloro-1-(2-chloroethyl)azetidin-2-ones into 3-aryl-2-(ethylamino)propan-1-ols via intermediate 1-(1-aryl-2-chloro-3-hydroxypropyl)aziridines and trans-2-aryl-3-(hydroxymethyl)aziridines

trans-4-Aryl-3-chloro-1-(2-chloroethyl)azetidin-2-ones, prepared through cyclocondensation of chloroketene and the appropriate imines in a diastereoselective way, were unexpectedly transformed into 3-aryl-2-(ethylamino)propan-1-ols using LiAlH(4) in THF under reflux. A stepwise analysis showed that the initially formed 1-(1-aryl-2-chloro-3-hydroxypropyl)aziridines were converted into trans-2-aryl-3-(hydroxymethyl)aziridines, most probably via N-spiro bis-aziridinium intermediates, which were subsequently prone to undergo ring opening by LiAlH(4) to afford 3-aryl-2-(ethylamino)propan-1-ols.