Tandem Pd(II)-Catalyzed Vinyl Ether Exchange−Claisen Rearrangement as a Facile Approach to γ,δ-Unsaturated Aldehydes
作者:Xudong Wei、Jon C. Lorenz、Suresh Kapadia、Anjan Saha、Nizar Haddad、Carl A. Busacca、Chris H. Senanayake
DOI:10.1021/jo062548f
日期:2007.5.1
A sequential allyl vinyl ether formation−Claisen rearrangement process catalyzed by a palladium(II)−phenanthroline complex is reported. The effects of allylic alcohol structure, type of vinylating agent, and palladium catalysts are discussed. This method provides a convenient approach to γ,δ-unsaturated aldehydes under mild conditions that avoid the use of toxic Hg(II) catalysts. The new methodology
The chemistry of spiroacetals. Approaches to the novel 1,6,8-trioxadispiro[4.1.5.3]pentadecane ring system
作者:Raymond Baker、Margaret A. Brimble
DOI:10.1039/c39850000078
日期:——
The synthesis of saturated bis-spiroacetal (11) from an intramolecular catalysed cyclization of a keto-epoxide together with the preparation of unsaturated bis-spiroacetal (16)via a Barton-type reaction of substituted hydroxy spiroacetal (15) highlight a means of constructing the above-named ringsystem.
The 17ONMRspectra of a number of alkyl‐ and phenyl‐substituted divinyl ethers were recorded in CDCl3 solution. The relationship between chemical shift and the number, nature and position of substituents was explored. The shift values, falling in the range δ 100–140 ppm, were found to be remarkably insensitive to the electronic and stereochemical effects of substituents. The narrow range of chemical
Selective photocycloadditions of biacetyl to allyl vinyl ethers: The synthesis of 2-alkoxyoxetanes as thromboxane A2 analogues.
作者:Howard A.J. Carless、G.K. Fekarurhobo
DOI:10.1016/s0040-4039(00)98748-3
日期:1985.1
Uv irradiation of biacetyl in the presence of the β,β-disubstituted vinylethers (2) and (9) gives reactive 2-alkoxyoxetanes (3) and (10), respectively; photoexcited biacetyl reacts chemoselectively with methallyl vinylethers (7) and (9) at the vinylether double bond.