6-(3-Cyanopropyl)-2-vinyl tetrahydropyran-2-ol and its tautomer
申请人:Hoffmann-La Roche Inc.
公开号:US03994930A1
公开(公告)日:1976-11-30
A multi-step, stereospecific total synthesis of steroids utilizing intermediates having a cyanoalkyl A-ring precursor is disclosed. The initial starting materials for this process are the relatively inexpensive and commercially available reagents .gamma.-butyrolactone and sodium cyanide. The process is suitable for the preparation of racemic or optically active, medicinally valuable steroids, particularly 19-norsteroids. It is a feature of this process that conditions employed during the multiple step synthesis are selected so as to retain the normally labile nitrile group even during hydrogenation and hydrolysis steps. In this manner, it is possible to employ the nitrile group as an A-ring precursor without resorting the protective groups as was heretofore found necessary in previous steroid total synthesis processes.