Reactions of Oxosulfonium Ylides With Ketenes. The Formation of Enol-Lactones and Dihydrofuranones

Abstract

The reaction of diphenyloxosulfonium p-methoxyphenacylide with dialkyl- or alkylaryl-ketenes gave enol-lactones in good yields, whereas the reaction of diphenyloxosulfonium phenacylide with diarylketenes led to dihydrofuranones besides the enol-lactones.

Visible-Light-Mediated Strategies to Assemble Alkyl 2-Carboxylate-2,3,3-Trisubstituted β-Lactams and 5-Alkoxy-2,2,4-Trisubstituted Furan-3(2H)-ones Using Aryldiazoacetates and Aryldiazoketones

“…In this context, , we became interested in the blue-light-mediated photolysis of aryldiazoacetates 1 to afford carbenes 2 , which could sequentially react either with azides 3 or sulfoxides 5 to afford imines 4 or sulfoxonium ylides 6 , , respectively. Sequential reaction with diazoketones 7 , also under blue light irradiation, could then potentially convert imines 4 to β-lactams 9 (some members of this class of compounds have been previously accessed via metal catalysis) , and sulfoxonium ylides 6 to furan-3­(2H)-ones 10 by taking advantage of a ketene intermediate 8 generated from a photochemically promoted Wolff rearrangement (Scheme ).…”