The invention is directed to a process and intermediates for the preparation of 1&agr;,23(S),25-trihydroxycholecalciferol and 1&agr;, 23(R),25-trihydroxycholecalciferol. The end-products, 1&agr;,23(S),25- trihydroxycholecalciferol and 1&agr;,23(R),25-trihydroxycholecalciferol, are useful ...