Efficient synthesis of α-alkylidene-β-lactams via NaOH-promoted intramolecular aza-Michael addition of α-carbamoyl ketene-S,S-acetals in aqueous media

Recent developments of ketene dithioacetal chemistry

Ketene dithioacetals are versatile intermediates in organic synthesis. Extensive research, since the last decade, has given rise to new prospects in their chemistry. The objective of this review is twofold: first, to highlight the new prospects in the chemistry of functionalized ketene dithioacetals, and second, to provide an intrinsic link between ketene dithioacetal groups and a variety of other functional groups, which has brought out many new facts that will assist in future designs.

Ring-enlargement of dimethylaminopropenoyl cyclopropanes: an efficient route to substituted 2,3-dihydrofurans

A convenient and efficient synthesis of substituted dihydrofurans is developed via ring-enlargement of 1-dimethylaminopropenoyl-1-carbamoyl/benzoyl cyclopropanes catalyzed by ammonium acetate in acetic acid with high regio- and stereoselectivity. Some of the newly synthesized substituted dihydrofurans are subjected to further synthetic transformation in the presence of NaOH (aq) in ethanol to afford the corresponding 5-aryl-2,3-dihydrofuro[3,2-c]pyridin-4(5H)-ones in high yields.