Lipase-catalyzed kinetic resolution of 3-chloro-2-hydroxyalkanoates. Its application for the synthesis of (−)-disparlure
摘要:
Reduction of 3-chloro-2-oxoalkanoates 1 with NaBH4 gave predominantly syn-3-chloro-2-hydroxyalkanoates 2 (synlanti=91/9-99/1) in 50-97% yields. Resolution of syn-2 by lipase-catalyzed transesterification gave (2S,3S)-2 and (2R,3R)-2-acetoxy-3-chloroalkanoates (2R,3R)-3. Total synthesis of (-)-disparlure, the pheromone of the gypsy moth was established from (2S,3S)-2g via 4 steps in 34.9% overall yield. (C) 1997 Elsevier Science Ltd. All rights reserved.
Highly enantioselective reduction of 3-chloro-2-oxoalkanoates with fermenting bakers' yeast. A new synthesis of optically active 3-chloro-2-hydroxyalkanoates and glycidic esters
Reduction of 3-chloro-2-oxoalkanoic esters with fermenting bakers' yeast gave optically active 3-chloro-2-hydroxyalkanoic esters 2 (anti(2S,3R)/syn (2S,3S) = 52:48-90:10) in 50-85% yields with >95% ee except for 43% ee of ethy syn-(2S,3S)-3-chloro-2-hydroxy-4 phenylbutanoate (2j). Compounds 2 were treated with NaOEt to give (E)-(2R,3S)-2,3-epoxyalkanoates 3 in 30-66% yields with 44-64% ee. Optically active 2,3-epoxy alcohols (cis-23, trans-23, and trans-25), key intermediates for the syntheses of (-)-disparlure (4), mosquito pheromone (5), and a component of passion fruit flavor (6), were prepared with more than 86% ee in high yields.
Lipase-catalyzed kinetic resolution of 3-chloro-2-hydroxyalkanoates. Its application for the synthesis of (−)-disparlure
作者:Sadao Tsuboi、Nobuyuki Yamafuji、Masanori Utaka
DOI:10.1016/s0957-4166(96)00529-0
日期:1997.2
Reduction of 3-chloro-2-oxoalkanoates 1 with NaBH4 gave predominantly syn-3-chloro-2-hydroxyalkanoates 2 (synlanti=91/9-99/1) in 50-97% yields. Resolution of syn-2 by lipase-catalyzed transesterification gave (2S,3S)-2 and (2R,3R)-2-acetoxy-3-chloroalkanoates (2R,3R)-3. Total synthesis of (-)-disparlure, the pheromone of the gypsy moth was established from (2S,3S)-2g via 4 steps in 34.9% overall yield. (C) 1997 Elsevier Science Ltd. All rights reserved.
A Practical Synthesis of Chiral 3-Chloro-2-hydroxyalkanoates and 2,3-Epoxyalcohols