The Reaction of Cyclopropanols with Burgess Reagent: A Reinvestigation and Correction
摘要:
The reaction of cyclopropanols with Burgess reagent yields the unusual sulfamates 8 and their N-methylated derivatives 9. Unlike a previous study, dicyclopropyl ether formation was not observed. Also, the mechanism of ether formation from a cyclopropanol precursor cannot follow an S(N)2 pathway with retention.
Action des dialkylcuprates de lithium sur les aldéhydes α,β -éthylénioues
作者:C. Chuit、J.P. Foulon、J.F. Normant
DOI:10.1016/0040-4020(80)80126-8
日期:1980.1
Nearly exclusive 1-4 addition produts obtained by action of lithium dialkylcuprates with α,β ethylenic aldehydes. Non polar solvents and low temperatures favour this reaction .Only α,β-ehylenic aldehydes having a trisubstituted double bond give a relatively important proportation of 1–2 addition product.
Copper-catalyzed conjugate addition of the Grignard reagents in the presence of Me3SiCl and HMPA proceeds in much higher yield than the reaction of conventional organocopper reagents and shows very good regio-, stereo-, and chemoselectivities.
An Alternative Procedure for the O-Trimethylsilylation of Enolates Generated by Copper-Catalyzed 1,4-Additions
作者:H. Andringa、I. Oosterveld、L. Brandsma
DOI:10.1080/00397919108021287
日期:1991.6
bromide has been successfully used as an additive instead of hexamethylphosphoric triamide in the O-trimethylsilylation of enolates generated by copper halide-catalyzed reaction of Grignardreagents with a number of α, β-unsaturated carbonyl compounds. Some conjugate additions also proceed satisfactorily in the absence of lithium bromide.