In situ generated or isolated dimethyldioxirane (1a) and methyl(trifluoromethyl)dioxirane (1b) efficiently afford oxidation of alkynes, most likely via oxirene intermediates, which rearrange into ketene or alpha,beta-unsaturated carbonyls, or else are further oxidized to alpha,beta-dicarbonyls. Diphenylacetylene and phenylacetylene yield mostly ketene derived products, whereas 8-hexadecyne (an internal dialkyl alkyne) gives 9-hexadecen-8-one (both trans and cis) as the main product. Reaction of cyclodecyne (a conformationally rigid cycloalkyne) with isolated 1b affords cis-bicyclo[5.3.0]decan-2-one (15) and cis-bicyclo[4.4.0]decan-2-one (16). which derive from the oxirene by stereoselective 1.5- and 1,6-transanular insertion, respectively.
Oxidation of alkynes by dioxiranes
Fusco C;
1992
Abstract
In situ generated or isolated dimethyldioxirane (1a) and methyl(trifluoromethyl)dioxirane (1b) efficiently afford oxidation of alkynes, most likely via oxirene intermediates, which rearrange into ketene or alpha,beta-unsaturated carbonyls, or else are further oxidized to alpha,beta-dicarbonyls. Diphenylacetylene and phenylacetylene yield mostly ketene derived products, whereas 8-hexadecyne (an internal dialkyl alkyne) gives 9-hexadecen-8-one (both trans and cis) as the main product. Reaction of cyclodecyne (a conformationally rigid cycloalkyne) with isolated 1b affords cis-bicyclo[5.3.0]decan-2-one (15) and cis-bicyclo[4.4.0]decan-2-one (16). which derive from the oxirene by stereoselective 1.5- and 1,6-transanular insertion, respectively.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
