Totally Selective Ring-Opening of Amino Epoxides with Ketones: A General Entry to Enantiopure (2R,3S)- and (2S,3S)-3-Aminoalkano-1,2-diols
摘要:
Transformation of enantiopure diastereoisomers (2R,1'S)- and (2S,1'S)-2-(1-aminoalkyl)epoxides into the corresponding 4-(1-aminoalkyl)-1,3-dioxolanes is achieved by reaction with different ketones in the presence of (BF3Et2O)-Et-.. The conversion takes place in very high yields. total selectivity, and without epimerization. A mechanism to explain this transformation is proposed. The obtained 1.3-dioxolanes can be deprotected. and (2R,3S)- and (2S,3S)-3-aminoalkano-1,2-diols were isolated.