A concise enantioselective synthesis of a key A-ring synthon for 1 alpha-hydroxyvitamin D3 compounds.
[figure: see text] This report describes a concise enantioselective synthesis of the A-ring synthon for the synthesis of 1 alpha-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.
Hiyamizu
H
H
Faculty of Pharmaceutical Sciences, Nagasaki University, Nagasaki 852, Japan.
Ooi
H
H
Inomoto
Y
Y
Esumi
T
T
Iwabuchi
Y
Y
Hatakeyama
S
S
D002117:Calcitriol / Q000031:analogs & derivatives*; D006887:Hydroxycholecalciferols / Q000138:chemical synthesis*; D013237:Stereoisomerism
D006887:Hydroxycholecalciferols; D002117:Calcitriol