1-Phenylthio-3-vinyl-3-cyclohexenol, a new reagent for bis-annelation of silyl enol ethers
作者:Olga Konstantinova、Florence C.E. Sarabèr、Enrique Melguizo、Ben J.M. Jansen、Aede de Groot
DOI:10.1016/j.tet.2005.11.060
日期:2006.2
1-Phenylthio-3-vinyl-cyclohex-1-en-3-ol (2) has been synthesized and investigated as a new bis-annelation reagent for silyl enol ethers. Reagent 2 can be synthesized by a Grignard reaction of vinyl magnesium bromide with 3-phenylthiocyclohexenone. The reaction with silyl enol ethers takes place under Lewis acid catalysis and generally proceeds in good yields. The resulting phenylthiodienes can be hydrolyzed
A short, flexible and efficient procedure has been developed for the synthesis of C17 substituted steroid skeletons and D-homo steroid skeletons using a ZnBr2 catalysed coupling of a silyl enol ether containing ring D precursor with a Torgov type reagent, followed by acid catalysed cyclisation of the adducts to (D-homo) steroid skeletons.