Disclosed herein is an improved and efficient process for synthesis of vitamin D3 and its analogue Calcifediol from Ergosterol. Particularly, the present invention discloses the synthesis of key intermediate 3β-tert-Butyldimethylsilyloxy-22-hydroxy-23,24-bisnorchola-5,7-diene (5), and novel intermediate β-tert-Butyldimethylsilyloxy-22-iodo-23,24-bisnorchola-5,7-diene (9) by a simple and cost effective process. The industrially viable processes for preparation of said intermediate(s) results in providing provitamins with various side chains and the desired products in high yield.
本文披露了一种改进和高效的合成
维生素D3及其类似物卡西酯醇(Calcifediol)的过程,该过程是从
麦角固醇(Ergosterol)中进行的。特别地,本发明披露了关键中间体3β-叔丁基二甲基
硅氧基-22-羟基-23,24-双去甲胆甾-5,7-二烯(5)的合成,以及新型中间体β-叔丁基二甲基
硅氧基-22-
碘代-23,24-双去甲胆甾-5,7-二烯(9)的合成,采用简单且具有成本效益的方法。用于制备该中间体的工业可行过程能够提供具有各种侧链的前
维生素和高产率的所需产品。