Synthesis of 4-Alkyl-4-alkoxybutenolides Having Unsaturated Side Chains via Chromium Carbene Complex Photochemistry: (+)-Cerulenin
作者:Tracey E. Kedar、Michael W. Miller、Louis S. Hegedus
DOI:10.1021/jo960664k
日期:1996.1.1
photochemical reaction between optically active ene carbamates and chromium alkoxycarbene complexes containing unsaturated aliphatic side chains was further developed. Although remote olefinic groups, including conjugated dienes, were tolerated, a homoallylic side chain underwent intramolecularreaction to give a strained cyclobutanone. (+)-Cerulenin was synthesized utilizing the photochemical reaction of an
Synthesis and Reactivity of Optically Active Spiroketals by Ring-Expansion of Chromium Carbene Complex-Derived Cyclobutanones
作者:Ana B. Bueno、Louis S. Hegedus
DOI:10.1021/jo971665v
日期:1998.2.1
Photolysis of cyclic chromium alkoxycarbene complexes with an optically active ene-carbamate gave spirofused, optically active cyclobutanones. Baeyer-Villiger ringexpansion followed by further functionalization gave optically active spiroketals. Photochemicalringexpansion of these spirofused cyclobutanones in the presence of acetic acid or thiophenol gave 2-acetoxy- or 2-(thiophenoxy)-4-spirofused