A new variant of Reformatsky-Claisen rearrangement is described. The reaction of an allyl α-bromo ester in the presence of indium(I) chloride provides a general entry into the functionalized synthon.
Bis(trimethylsilyl) ketene acetals react successively with
allylic acetates, in the presence of Pd(0) then with
H2O2, in the presence of methyltrioxorhenium, to give
δ-hydroxy-γ-lactones via γ-unsaturated
carboxylic acids.
A range of chiral hydrogen-bond-donating organocatalysts was tested in the Ireland-Claisenrearrangement of silyl ketene acetals. None of these organocatalysts was able to impart any enantioselectivity on the rearrangements. Furthermore, these organocatalysts slowed down the Ireland-Claisenrearrangement in comparison to an uncatalyzed reaction. The catalyst-free reaction proceeded well in green solvents
A new variant of the Reformatsky-Claisen rearrangement is described. The reaction of substituted allyl alpha-bromoacetates with indium and indium(III) chloride under ultrasonication provides a general entry into the functionalized synthon. (C) 2011 Elsevier Ltd. All rights reserved.
Competitive [1,3]- and [3,3]-sigmatropic rearrangements