Efficient 1,8- to 1,12-asymmetric induction in Grignard reactions of ω-keto esters by using BINOL or its 2′-oligoether derivatives as the chiral auxiliary
Abstract
Efficient diastereoselective alkylation of δ- and ε-keto acids with Grignard reagents was achieved in up to 97% de by conversion into the 2′-[3-(2-methoxyethoxy)propoxy]-(1,1′-binaphthyl)-2-ol esters, while the corresponding alkylation of ζ- to θ-keto acids could effectively be carried out in up to 88% de by simply using BINOL as the chiral auxiliary.