铬介导的乙酰氧基管形呋喃两种对映体的不对称合成。

Chromium-mediated asymmetric synthesis of both enantiomers of acetoxytubipofuran.

作者信息

Kündig E Peter, Cannas Rita, Laxmisha Mundruppady, Ronggang Liu, Tchertchian Sylvie

机构信息

Department of Organic Chemistry, University of Geneva, 30 Quai Ernest Ansermet, 1211 Geneva 4, Switzerland.

出版信息

J Am Chem Soc. 2003 May 14;125(19):5642-3. doi: 10.1021/ja029957n.

DOI:10.1021/ja029957n

PMID:12733897

Abstract

Both enantiomers of acetoxytubipofuran were synthesized using enantioselective and diastereoselective dearomatization sequences starting from the benzaldehyde chromium tricarbonyl complex. Following aldol condensation, a sequence involving Pd-catalyzed allylic substitution was used in the synthesis of the (-)-enantiomer, whereas the (+)-enantiomer was reached via an Eschenmoser-Claisen rearrangement. Chiroptical data show that a revision of the previously assigned absolute configuration of the natural product is required.

摘要

从苯甲醛三羰基铬配合物出发，通过对映选择性和非对映选择性脱芳构化序列合成了乙酰氧基管形呋喃的两种对映体。在羟醛缩合之后，合成（-）-对映体时使用了涉及钯催化烯丙基取代的序列，而（+）-对映体则通过埃申莫瑟-克莱森重排得到。手性光学数据表明，需要对天然产物先前指定的绝对构型进行修正。