Radical Rearrangement: A Strategy for Conversion of Cephalosporin to 1-Carba(dethia)cephalosporin

Autor:	Douglas O. Spry, Brown Raymond Frank, Noreen G. Halligan, Larry C. Blaszczak
Rok vydání:	2000
Předmět:	Cephem Diene Stereochemistry Radical Organic Chemistry Reactive intermediate Carbacephem Biochemistry Semisynthesis chemistry.chemical_compound chemistry Intramolecular force Drug Discovery medicine Rearrangement reaction medicine.drug
Zdroj:	Tetrahedron. 56:5679-5685
ISSN:	0040-4020
DOI:	10.1016/s0040-4020(00)00417-8
Popis:	A radical rearrangement approach to semisynthesis of the carbacephem class of β-lactam antibiotics is reported. The crucial bond construction in assembly of the carbacephem framework was accomplished by intramolecular C–C bond formation between an azetidin-2-one-4-yl and a pendant diene ester. This reactive intermediate was generated by fragmentation of a cephem derived radical followed by loss of sulfur dioxide. The radical precursor was prepared in 63% yield over four steps and the subsequent rearrangement reaction provided carbacephem products in a single step at 23% yield.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::d5a3699a4070ee581a1fb225b6332695 https://doi.org/10.1016/s0040-4020(00)00417-8 Zobrazit plný text záznamu Full Text from ScienceDirect