Addition of Ketones to 3-Alkyl-1H-phospholane Oxides in the Synthesis of Tetrasubstituted α-Hydroxyphospholane Oxides

An efficient atom-economical synthetic method has been proposed for the synthesis of stereoisomeric 3-alkyl-1-(α-hydroxydialkyl(diphenyl))phospholane oxides and 3-alkyl-1-(α-hydroxyalkylphenyl)phospholane oxides via the reaction of 3-alkyl-1H-phospholane oxides with aliphatic and aromatic ketones under mild conditions (20-22 °C, 12 h), conducted without the use of solvents or catalysts, achieving yields of 85-98%. Phosphorylation of acetylacetone by 3-alkyl-1H-phospholane oxides has been successfully achieved at both carbonyl groups. The mechanism of the addition of cyclic secondary phosphine oxides to ketones is discussed.