Ultrasonically Induced Conjugate Addition of Iodides to Electron-Deficient Olefins and Its Application to the Synthesis of Side-Chain Analogs of the Hormone 1α,25-Dihydroxyvitamin D3

Article abstract of DOI:10.1021/jo00053a023

A versatile method for the rapid construction of fragments related to the upper part of vitamin D₃ from the Lythgoe-Inhoffen diol is described.The key feature of the strategy is a new zinc-copper-induced conjugate addition of iodo triflate 10a to electron-deficient olefins under sonochemical aqueous conditions.These fragments are rapidly and efficiently transformed via the dienyne convergent approach to several derivatives of the hormone 1α,25-(OH)2-D₃ modified at C-25.