A Divergent Synthetic Strategy Based on the Regioselective Reductive Ring-Opening of a Cyclic 1,2-p-Methoxybenzylidene Acetal
Résumé
Dibenzyl-1-[(4R)-2-(4-methoxyphenyl)-1,3dioxolan-4-yl]ethanamine is obtained in five steps from an abromo-a¢-(R)-sulfinyl ketone and is used as a common intermediate for the synthesis of the p-methoxybenzyl-protected primary and secondary alcohols, (2R,3S)-3-(dibenzylamino)-2-[(4-methoxybenzyl)oxy]butan-1-ol and (2R,3S)-3-(benzylamino)-1-[(4-methoxybenzyl)oxy]butan-2-ol, respectively. These alcohols are further exploited as precursors for the synthesis of a fully protected syn-3amino-2-hydroxybutanoic acid and an N-benzyl 2-hydroxymethylaziridine.