ol006982u_si_001.pdf (62.71 kB)
A Concise Enantioselective Synthesis of a Key A-Ring Synthon for 1α-Hydroxyvitamin D3 Compounds
journal contributionposted on 2001-01-12, 00:00 authored by Hiroko Hiyamizu, Hidenori Ooi, Yoko Inomoto, Tomoyuki Esumi, Yoshiharu Iwabuchi, Susumi Hatakeyama
This report describes a concise enantioselective synthesis of the A-ring synthon for the synthesis of 1α-hydroxyvitamin D3 compounds. The synthesis involves two notable transformations: (i) stereoselective construction of the enol triflate from the vinyl ketone by Michael addition of Ph2P(O)Li followed by in situ triflation of the resulting enolate and (ii) palladium-catalyzed Heck type cyclization of the enol triflate.