Expedited Approach to the Vitamin D trans-Hydrindane Building Block from the Hajos Dione. Comparative Study on Various Methods for the Selective Deoxygenation of One of the Hydroxy Groups in a

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• 作者：Pawe<img src="http ; //pubs.acs.org/images/entities/lstrok.gif" border="0"> Chochrek ; Jerzy Wicha
• 刊名：Journal of Organic Chemistry
• 出版年：2007
• 出版时间：July 6, 2007
• 年：2007
• 卷：72
• 期：14
• 页码：5276 - 5284
• 全文大小：215K
• 年卷期：v.72,no.14(July 6, 2007)
• ISSN：1520-6904

文摘

BLE><IMG SRC="/isubscribe/journals/joceah/72/i14/figures/jo070685mn00001.gif" ALIGN="left" HSPACE=5>1,25-Dihydroxyvitamin D₃ (calcitriol, 1) is a bioregulator important for the treatment of various humanmetabolic diseases and biomedical research. Herein, we report an efficient diastereoselective approachto the key trans-hydrindane building block for calcitriol synthesis (2a) starting from the readily accessibleoptically active tetrahydroindenedione derivative (Hajos dione, 3). It was found that epoxide ring openingin a related hydroxy epoxide (7) with sodium cyanoborohydride-BF₃ × Et₂O occurs by hydride anionaddition at the ring juncture position to produce a vicinal diol with the trans-hydrindane ring system(6a). Four methods for selective deoxygenation of the sterically less shielded hydroxy group in diol 6awere examined with an approach based on a cyclic sulfate of the diol as the most efficient and operationallyconvenient method.