Synthesis of some fenchyl-substituted alkenes and enol-ethers containing 3-oxyphenyl substituents by the Barton-Kellogg reaction

Journal of the Brazilian Chemical Society

Bastos, Erick L.¹  Günther, Wolfgang¹  Weiss, Dieter¹  Baader, Wilhelm Josef¹  Friedrich-Schiller Universität Jena, Jena, Germany¹  Bartoloni, Fernando H.¹  Universidade Federal do ABC, Santo André, Brazil¹  Ciscato, Luiz Francisco M. L.¹  Universidade de São Paulo, São Paulo, Brazil¹  Beckert, Rainer¹ 

关键词: Barton-Kellogg olefination;    hindered alkenes;    diazo compounds;    thioketone;    fenchone;   

DOI  :  10.1590/S0103-50532010001000014

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

The synthesis of one fenchyl-substituted alkene and two enol-ethers, containing 3-oxyphenyl substituents by the Barton-Kellogg reaction is described. The tri-substituted aromatic fenchyl-alkene 1a was prepared in 53% yield from thiofenchone and a diazoanisole; whereas enol-ethers 1b and 1c were obtained (95 and 75% yield, respectively) using an inverse approach based on diazofenchone and aromatic thionoesters. A mixture of Z and E isomers was obtained in all cases; isomer attribution and quantification has been carried out by analysis of NMR spectroscopic data assisted by theoretical calculations (E/Z ratio: 1a = 0.72, 1b = 2.2, 1c = 1.8). Reaction proceeds with low stereoselectivity leading to the preferential formation of diastereoisomeric olefins and enol-ethers where the aromatic substituent resides at the side of the two fenchyl methyl groups.

【 授权许可】

Unknown