O,O-Acetal Formation of exo-Annelated Octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-ol with Lactic Acid and Phenyllactic Acid Derivatives

Abstract

Acetals of a series of substituted lactic acid derivatives were formed with enantiopure lactol 1. 1H and 13C NMR spectroscopic data of the anomerically pure O,O-acetals are compared in order to assign the absolute configuration of the O-protected lactic acid derivatives and for the determination of enantiomeric excesses. The results are supported by molecular modeling studies.