摘要 已经从 Cirsium dipsacolepis 的根中分离出两种新的和六种已知的脂肪醛,即。7-辛烯醛、(2 E )-2,8-壬二烯醛、(2 E )-2,9-癸二烯醛、(2 E )-2,10-十一烯醛、(2 E ,4 E )-2,4,10 -十一碳三烯醛、(2 E ,4 E )-2,4,11-十二碳三烯醛、(2 Z ,4 Z )-2,4,11-十二碳三烯醛和 (2 E ,4 Z )-2,4,11-十二碳三烯醛. 从烷烃-α,ω-二炔中立体选择性地鉴定和合成醛。
Enantioselective Organocatalytic Cyclopropanations. The Identification of a New Class of Iminium Catalyst Based upon Directed Electrostatic Activation
作者:Roxanne K. Kunz、David W. C. MacMillan
DOI:10.1021/ja042774b
日期:2005.3.1
A new method for enantioselectiveorganocatalyticcyclopropanation is described. This study outlines the identification of a new class of iminium catalyst based on the concept of directed electrostatic activation (DEA). This novel organocatalytic mechanism exploits dual activation of ylide and enal substrates through a proposed electrostatic activation and stereodirected protocol. Formation of trisubstituted
描述了一种对映选择性有机催化环丙烷化的新方法。本研究概述了基于定向静电活化 (DEA) 概念的新型亚胺催化剂的鉴定。这种新颖的有机催化机制通过提出的静电激活和立体定向协议利用了叶立德和 enal 底物的双重激活。对多种α、β-不饱和醛和锍叶立德可形成具有高水平对映和非对映诱导的三取代环丙烷。此外,机理研究发现,该环丙烷化反应表现出与提议的 DEA 步骤一致的对映选择性和反应性特征。
Bohlmann et al., Chemische Berichte, 1957, vol. 90, p. 1661,1667
作者:Bohlmann et al.
DOI:——
日期:——
Intramolecular Diels-Alder reactions of ethyl 2,4,9-decatrienoate and 2,4,10-undecatrienoate