Efficient 1,8- and 1,9-asymmetric inductions in the Grignard reaction of delta- and epsilon-keto esters of 1,1 '-binaphthalen-2-ols with an oligoether tether as the 2 '-substituent: application to the synthesis of (-)-malyngolide

Efficient 1,8- and 1,9-asymmetric inductions in the Grignard reaction of po dand-type delta- (3,4) and epsilon -keto esters (5,6) are achieved in the p resence of MgBr2. OEt2 with up to 97 and 82% optical yields, respectively, by using 2'-[3-(2-methoxyethoxy)propoxy]-1,1'-binaphthalen-2-ol as the chir al auxiliary. The 1,8-asymmetric inductive Grignard reaction has been advan tageously utilized in the key step of a synthesis of (-)-malyngolide.