| 摘要 |
Novel 1 alpha ,3 beta -dihydroxy-24-oxocholesta-5,7-diene and the hydroxyl group-protected derivatives thereof. Said novel 1 alpha -hydroxy-24-oxovitamin D3 and said novel intermediates are also useful as the intermediates of 1 alpha ,24-dihydroxyvitamin D3. 1 alpha ,3 beta -Dihydroxy-24-oxocholesta-5,7-diene and the hydroxyl group-protected derivatives thereof are prepared from fucosterol via 1 alpha ,3 beta -diprotected hydroxy-24(24)-ethylenedioxycholest-5-ene. 1 alpha -hydroxy-24-oxovitamin D3 is prepared by irradiation with ultraviolet rays to 1 alpha ,3 beta -dihydroxy-24-oxocholesta-5,7-diene or a hydroxyl group-protected derivatives thereof, isomerization using heat energy, and, when necessary, elimination of the protecting groups.
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