Enantioselective Synthesis of Optically Active O ‐Benzoyl‐Protected α‐Hydroxyl‐β,γ‐Unsaturated Acids with Chiral Induction of ( S )‐Glyceraldehyde Acetonide

α‐Hydroxyl‐β,γ‐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 α‐hydroxyl‐β,γ‐unsaturated acids is presented. Chiral induction was achieved using ( S )‐glyceraldehyde acetonide as chiral source together with ClTi(O i ‐Pr) 3 as coordinating agent. The overall synthetic route included 6 simple steps, and six optically active O ‐benzoyl‐protected α‐hydroxyl‐β,γ‐unsaturated acids 1 a ‐ 1 f (99% ee ) were prepared in up to 53% yield.