Asymmetric Induction in the [2,3] Wittig Rearrangement The Stereoselective Synthesis of Unsaturated Alcohols with Three Contiguous Stereogenic Centers

The [2,3] Wittig rearrangements of the lithio anions of the allyl propargyl ethers 7 are diastereoselective. A chiral dioxolane in the allyl moiety of 7 controls the configuration of the vinyl group at one of the newly formed stereogenic centers through asymmetric induction. Proper choice of cis‐ or trans‐configurated starting material generates anti (12) or syn (13) 1,3‐dioxygenated systems, respectively, in high selectivity. – It is suggested that the magnitude of the vicinal coupling constant 3JOH,H of the hydroxylic proton can be used to assign the stereochemistry in epimeric syn and anti γ‐alkoxy alcohols.