Efficient enantiospecific synthesis of key A-ring synthons for the preparation of 1.alpha.,25-dihydroxyvitamin D3 using a chromium(II)-mediated reaction
Efficient enantiospecific synthesis of key A-ring synthons for the preparation of 1.alpha.,25-dihydroxyvitamin D3 using a chromium(II)-mediated reaction
A novel synthesis of an a-ring precursor to 1α-hydroxyvitamin D
作者:Johny De Schrijver、Pierre J. De Clereq
DOI:10.1016/s0040-4039(00)79355-5
日期:1993.7
A novel synthesis of the known, 1alpha-hydroxyvitamin D A-ring precursor 10, in racemic form, is described based upon (i) the stereoselective cycloaddition of allene-dienophile 2 onto 3-trimethylsilyloxyfuran 1 to give 3, and (ii) the samarium iodide induced reductive opening of the oxygen bridge in 4 to yield hydroxyketone 5, as key-steps.