Asymmetric synthesis of protected α-alkyl-β-amino-δ-hydroxy esters by stereocontrolled elaboration of THYM*

Highly diastereoselective internal Michael addition of the carbamate moiety of enoate 1b [derived from asymmetrized tris(hydroxymethyl)methane (THYM*)] leads to oxazinone 4, which can, in turn, be alkylated with moderate to good diastereoselectivity in the position α to the ester moiety to give protected anti,anti α-alkyl-β-amino-δ-hydroxy esters.