Totally selective ring-opening of amino epoxides with ketones: a general entry to enantiopure (2R,3S)- and (2S,3S)-3-aminoalkano-1,2-diols.
[Reaction: see text] 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 BF3.Et2O. 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.
Concellón
José M
JM
Departamento de Química Orgánica e Inorgánica, Facultad de Química, Universidad de Oviedo, Julián Clavería, 8, 33071 Oviedo, Spain. jmcg@fq.uniovi.es
Suárez
José Ramón
JR
García-Granda
Santiago
S
Díaz
M Rosario
MR