Efficient 1,8- and 1,9-asymmetric inductions in the Grignard reaction of δ- and ɛ-keto esters of 1,1′-binaphthalen-2-ols with an oligoether tether as the 2′-substituent: application to the synthesis of (−)-malyngolide
作者:Masamitsu Date、Yasufumi Tamai、Tetsutaro Hattori、Hideki Takayama、Yoshinori Kamikubo、Sotaro Miyano
DOI:10.1039/b100497m
日期:——
Efficient 1,8- and 1,9-asymmetric inductions in the Grignard reaction of podand-type δ- (3,4) and ε-keto esters (5,6) are achieved in the presence of MgBr2·OEt2 with up to 97 and 82% optical yields, respectively, by using 2â²-[3-(2-methoxyethoxy)propoxy]-1,1â²-binaphthalen-2-ol as the chiral auxiliary. The 1,8-asymmetric inductive Grignard reaction has been advantageously utilized in the key step of a synthesis of (â)-malyngolide.
在格里纳德反应中,使用2'-[3-(2-甲氧基乙氧基)丙氧基]-1,1'-联萘-2-醇作为手性辅助剂,在MgBr2·OEt2存在下,实现了高效的1,8-和1,9-不对称诱导,分别达到了97%和82%的光学产率。1,8-不对称诱导的格里纳德反应已成功应用于合成(-)-马灵果内酯的关键步骤中。