Structural effects on sigmatropic shifts in heteroaromatic allyl ethersElectronic supplementary information (ESI) available: selected crystal data for compound 7. See http://www.rsc.org/suppdata/p1/b1/b102674g/
作者:Nuna C. P. Araújo、Pedro M. M. Barroca、Jamie F. Bickley、Amadeu F. Brigas、M. Lurdes S. Cristiano、Robert A. W. Johnstone、Rui M. S. Loureiro、Paula C. A. Pena
DOI:10.1039/b102674g
日期:2002.4.26
In contrast to the known thermal, exclusively [3,3], O- to N- rearrangement of allyl groups in phenyltetrazoles (1, Scheme 1), the comparable migration of the allyl group in pseudosaccharyl ethers (3; Scheme 2) has been shown to proceed through both [1,3]- and [3,3]-mechanisms, 4, 5; for the pseudosaccharyl derivative of the natural product myrtenol (6; Scheme 3) only the product 7 of a [1,3]-shift has been observed; crystallographic data and theoretical calculations provide an explanation of this ease of [1,3]-isomerization and the observed selectivity as being due to conformational constraints and electronic factors.
与已知的苯基四唑(1,方案 1)中烯丙基的热重排(完全是[3,3]、O-到 N-重排)不同,假糖基醚(3;方案 2)中烯丙基的类似迁移已被证明是通过[1,3]和[3,3]两种机制进行的,4,5;晶体学数据和理论计算解释了[1,3]异构化的难易程度和观察到的选择性是由构象限制和电子因素造成的。