Triphosgene: a versatile reagent for the synthesis of azetidin-2-ones
摘要:
An efficient use of triphosgene, as an acid activator, for the synthesis of substituted azetidin-2-ones via ketene-imine cyclo-addition reaction using various acids and imines have been described. (C) 2002 Elsevier Science Ltd. All rights reserved.
Synthesis of 4-Unsubstituted β-Lactams<i>via</i>Dithiocarbonimidates
作者:S. D. Sharma、Usha Mehra、J. P. S. Khurana、S. B. Pandhi
DOI:10.1055/s-1987-28144
日期:——
Cycloaddition of dithiocarbonimidate 1 to the ketene generated in situ from phenoxyacetylchloride in the presence of triethylamine affords the 4-dithioalkyl-2-azetidinones 2 in good yields. Facile conversion of 2 to the 4-unsubstituted ß-lactams 3 can be accomplished by desulfurization with Raney-Nickel. Formation of several interesting products during attempts to bring a carbonyl function at C-4 in 2 has also been described.
An efficient use of triphosgene, as an acid activator, for the synthesis of substituted azetidin-2-ones via ketene-imine cyclo-addition reaction using various acids and imines have been described. (C) 2002 Elsevier Science Ltd. All rights reserved.
A Facile Synthesis of Azetidine-2,4-diones
作者:S. S. Bari、I. R. Trehan、A. K. Sharma、M. S. Manhas
DOI:10.1055/s-1992-26128
日期:——
Azetidine-2,4-diones 6 can be conveniently synthesized by mild oxidative hydrolysis of 4,4-bis(alkylthio)azetidin-2-ones 5 using N-bromosuccinimide.