Synthèse régiosélective par voie organomagnésienne de 2-(1,1-dialkylprop-2-ényl)-4,5-dihydrothiazoles et oxazoles, précurseurs d'acides β-éthyléniques α,α-disubstitués
摘要:
The synthesis of new 4,5-dihydrothiazoles (or oxazoles) starting from 2-methylthio-4,5-dihydrothiazoles (or oxazoles) and beta,beta-disubstituted allylic Grignard reagents has been described. Acidic hydrolysis of many of these heterocycles leads to the corresponding alpha, alpha-disubstituted beta-ethylenic carboxylic acids.
Alkylation of lithium dienediolates of butenoic acids. Regioselectivity effects of structure and leaving group of the alkylating agent
作者:Maria J. Aurell、Salvador Gil、Ramon Mestres、Margarita Parra、Lilian Parra
DOI:10.1016/s0040-4020(98)00149-5
日期:1998.4
Regioselectivity of alkylation of but-2-enoic acids 1 and 2 by alkyl halides strongly depends on the reactivity of the electrophile. High α selectivity results for saturated alkyl halides, whereas poor α-selectivity is obtained for highly reactive allyl and benzyl halides. For reactive alkylating halides selectivity is partly governed by the ion pairing aggregates of the dienediolates. Lithium bromide
Synthèse régiosélective par voie organomagnésienne de 2-(1,1-dialkylprop-2-ényl)-4,5-dihydrothiazoles et oxazoles, précurseurs d'acides β-éthyléniques α,α-disubstitués
作者:Joëlle Laduranty、Francis Barbot、Léone Miginiac
DOI:10.1016/0022-328x(91)83171-y
日期:1991.3
The synthesis of new 4,5-dihydrothiazoles (or oxazoles) starting from 2-methylthio-4,5-dihydrothiazoles (or oxazoles) and beta,beta-disubstituted allylic Grignard reagents has been described. Acidic hydrolysis of many of these heterocycles leads to the corresponding alpha, alpha-disubstituted beta-ethylenic carboxylic acids.
The Synthesis and Resolution of Methylethylisobutylacetic Acid