Keywords: Amino acids / Asymmetric synthesis / Carboxylic acids / Glycine equivalent / α-Hydroxy acidsThe chiral oxazinone 2 has been developed as a new chiral glycine equivalent for the asymmetric synthesis of mono-and disubstituted α-amino acids. It is derived from the α-hydroxycarboxylic acid 1, which serves as a chiral auxiliary, and is easily accessible in enantiomerically pure form by optical resolution of the racemic compound (RS)-1. For alkylation reactions, 2 was deprotonated with sBuLi or phosphazenic base. Subsequent treatment with alkyl halides yielded the monosubstituted compounds 13/14a−c, e, f, (ent)-13d, (ent)-14d, while a second alkylation step, via the corresponding enolates, provided the disubstituted compounds 17/18a−d. Both alkylation steps proceeded with good yields and excellent diastereoselectivities (up to 99% de) and even less reactive electrophiles such as isopropyl iodide could be used. The results obtained in this reaction supported the assumption that the enolate of 2, as well as those of the monosubstituted derivatives of 2, have less tendency to form the aggregates that hamper alkylation reactions with other systems with higher oxygen content. From the major diastereomers of both
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.