180153-01-9Relevant academic research and scientific papers
Synthesis and Reactivity of Optically Active Spiroketals by Ring-Expansion of Chromium Carbene Complex-Derived Cyclobutanones
Bueno, Ana B.,Hegedus, Louis S.
, p. 684 - 690 (2007/10/03)
Photolysis of cyclic chromium alkoxycarbene complexes with an optically active ene-carbamate gave spirofused, optically active cyclobutanones. Baeyer-Villiger ring expansion followed by further functionalization gave optically active spiroketals. Photochemical ring expansion of these spirofused cyclobutanones in the presence of acetic acid or thiophenol gave 2-acetoxy- or 2-(thiophenoxy)-4- spirofused tetrahydrofurans. Elimination of the thiophenoxy group gave a 3,4-dihydrofuran that underwent Heck arylation and photochemical cycloaddition with chromium carbene complexes to give cyclobutanones.
Synthesis of 4-alkyl-4-alkoxybutenolides having unsaturated side chains via chromium carbene complex photochemistry: (+)-cerulenin
Kedar, Tracey E.,Miller, Michael W.,Hegedus, Louis S.
, p. 6121 - 6126 (2007/10/03)
The 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 intramolecular reaction to give a strained cyclobutanone. (+)-Cerulenin was synthesized utilizing the photochemical reaction of an alkynylcarbene complex with an optically active ene carbamate and the bis(π-crotyl)nickel halide alkylation of a vinyl bromide as key steps.
