Enantioselective Synthesis of Optically Active O-Benzoyl-Protected alpha-Hydroxyl-, beta-Unsaturated Acids with Chiral Induction of (S)-Glyceraldehyde Acetonide

摘要

alpha -Hydroxyl-beta,gamma-unsaturated acids are usually present in biologically active natural products and medicines, and serve as valuable building blocks in synthetic organic chemistry. A new method for the synthesis of O-benzoyl-protected -hydroxyl-,-unsaturated acids is presented. Chiral induction was achieved using (S)-glyceraldehyde acetonide as chiral source together with ClTi(Oi-Pr)(3) as coordinating agent. The overall synthetic route included 6 simple steps, and six optically active O-benzoyl-protected -hydroxyl-,-unsaturated acids 1a-1f (99 ee) were prepared in up to 53 yield.