Diastereoselective Additions of Allylmagnesium Reagents to α-Substituted Ketones When Stereochemical Models Cannot Be Used
作者:Nicole D. Bartolo、Krystyna M. Demkiw、Elizabeth M. Valentín、Chunhua T. Hu、Alya A. Arabi、K. A. Woerpel
DOI:10.1021/acs.joc.1c00553
日期:2021.5.21
allylmagnesium reagents with chiral ketones cannot be easily explained by stereochemical models. Competition experiments indicate that the complexation step is not reversible, so nucleophiles cannot access the widest range of possible encounter complexes and therefore cannot be analyzed easily using available models. Nevertheless, additions of allylmagnesium reagents to a ketone can still be stereoselective
The cyclization reaction of diallyldibutyltin and α- or γ-halo ketones, especially chloro-substituted ketones, effectively proceeds in the presence of a catalytic amount of tetraethylammonium chloride, producing the corresponding 2-allyloxiranes or 2-allyltetrahydrofurans in high yield, respectively. β-Chloro ketones give the corresponding allyl alcohols.