A Bidirectional SE鈥?Strategy for 1,5-syn and 1,5-anti Stereocontrol toward the Synthesis of Complex Polyols

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• 作者：David R. Williams ; Christopher D. Claeboe ; Bo Liang ; Nicolas Zorn ; Nicholas S. C. Chow
• 刊名：Organic Letters
• 出版年：2012
• 出版时间：August 3, 2012
• 年：2012
• 卷：14
• 期：15
• 页码：3866-3869
• 全文大小：281K
• 年卷期：v.14,no.15(August 3, 2012)
• ISSN：1523-7052

文摘

Studies report a bidirectional S_E鈥?strategy applicable for the stereocontrolled synthesis of nonracemic 1,5-syn and 1,5-anti diols and their derivatives. Nonracemic 1,3,2-diazaborolidine auxiliaries are incorporated by chemoselective tin鈥揵oron exchange to provide reactive allylic boranes. The convergent pathway utilizes sequential reactions with two aldehydes producing stereochemical outcomes from cyclic, closed, and open transition state preferences, respectively. Synthesis of fragment 16 of peloruside A is accomplished in four steps from readily available aldehydes 9 and 13.