Enzyme-catalyzed resolution of 3,8-dioxatricyclo[3.2.1.02,4]octane-6-carboxylic esters and the application to the synthesis of 3-epishikimic acid
作者:Manabu Hamada、Yoshikazu Inami、Yasuhito Nagai、Toshinori Higashi、Mitsuru Shoji、Seiichiro Ogawa、Kazuo Umezawa、Takeshi Sugai
DOI:10.1016/j.tetasy.2009.07.049
日期:2009.9
3,8-Dioxatricyclo[3 2 1 0(2 4)]octane-6-carboxylic acid, whose racemic form is readily available on a large scale, is a versatile starting material for the synthesis of carbasugars and carbocyclic biologically active natural products. In this study, the enzyme-catalyzed kinetic resolution was attempted on a variety of corresponding carboxylic esters. The hydrophobic and hydrophilic properties of ester substituents greatly affected the rate of reaction and the enantioselectivity. Hydrolysis of the corresponding 2'-chlotoethyl ester with pig liver esterase worked well in a highly enantioselective manner (E = 116) to give the hydiolyzate (90.6% ee) and unreacted ester recovery (99.4% ee). The hydrolyzate is a piecursor for (-)-oseltamivir phosphate, and a route to (3S,4S,5R)-(-)-3-epishikimic acid was developed from the recovered ester. (C) 2009 Elsevier Ltd All rights reserved