1.ALPHA.,24(S)-DIHYDROXY VITAMIN D2, ITS FORMATION AND USE

摘要

1.alpha.,24(S)-Dihydroxy vitamin D2 which is useful as an active compound of pharmaceutical compositions for the treat-ment of disorders of calcium metabolism and for various skin disorders. The invention also includes preparation of sym-thetic 1.alpha.,24(S)-dihydroxy vitamin D2 starting from ergosterol which is converted in six steps to 24-hydroxyergosterol. 24-Hy-droxyergosterol is irradiated and thermally converted to 24-hydroxy vitamin D2 which is converted in six steps to 1.alpha.,24(S)-dihydroxy vitamin D2. The syntheses also produce novel intermediates.