γ-Oxygenation of α,β-Unsaturated Esters by Vinylogous O-Nitroso Mukaiyama Aldol Reaction
摘要:
A practical procedure has been developed for gamma-oxygenation of alpha,beta-unsaturated esters by a vinylogous O-nitroso Mukaiyama aldol reaction followed by a one-pot N-O bond heterolysis of the in situ generated gamma-aminoxy-alpha,beta-unsaturated esters.
Lewis Base Activation of Lewis Acids. Vinylogous Aldol Reactions
作者:Scott E. Denmark、Gregory L. Beutner
DOI:10.1021/ja035448p
日期:2003.7.1
A highly regioselective vinylogous aldol reaction catalyzed by SiCl4 and a chiral phosphoramide (R,R)-5, providing delta-hydroxy enones for a variety of aldehyde and dienol ether structures, has been developed. Low catalyst loadings (1 mol %) can be employed, giving the products in good yields, excellent enantioselectivities, and in some cases excellent anti diastereoselectivities. Both simple ester-derived