Steroid derivatives and processes of preparing same.

摘要

New processes for preparing new steroid derivatives including ergosta-1,5,7,22-tetraen-3 beta -ol, 1 alpha -hydroxy-ergosteryl diacetate, etc. which are useful intermediates in the synthesis of 1 alpha -hydroxy vitamin D2. The processes include the new steps of reacting ergosta-1,4,6,22-tetraen-3-one with isopropenyl acetate in the presence of an acid catalyst followed by reduction to ergosta-1,5,7,22-tetraen-3 beta -ol. The overall yield leading to 1 alpha -hydroxy vitamin D2 is dramatically increased.