The Cu(OTf)<sub>2</sub>- and Yb(OTf)<sub>3</sub>-Catalyzed Claisen Rearrangement of 2-Alkoxycarbonyl-Substituted Allyl Vinyl Ethers
作者:Martin Hiersemann、Lars Abraham
DOI:10.1021/ol006760w
日期:2001.1.1
[figure: see text] The Cu(OTf)2- and Yb(OTf)3-catalyzed Claisen rearrangement of 2-alkoxycarbonyl-substituted allylvinylethers has been developed. Reactivity and stereoselectivity strongly depend on the substrate structure.
Synthesis of α-Allyloxy-Substituted α,β-Unsaturated Esters via Aldol Condensation. Convenient Access of Highly Substituted Allyl Vinyl Ethers
作者:Martin Hiersemann
DOI:10.1055/s-2000-6424
日期:——
α-Allyloxy-substituted α,β-unsaturated esters 1a - r have been prepared in 5 steps from commercially available starting materials. The key sequence of the synthesis is an aldol addition between an α-allyloxy-substituted ester 2a - i and an aldehyde R1CHO followed by mesylation and DBU mediated elimination to afford the 2-alkoxycarbonyl-substituted allyl vinyl esters 1a - r. The E/Z ratio of the newly generated vinyl ether double bond is apparently determined by the steric bulk of the vinyl ether double bond substituent R1. Z:E ratios from 3:2-9:1 were obtained.