Synthesis of adamantylglycine using a diastereoselective grignard-to-nitrone addition

Article abstract of DOI:10.1055/s-0030-1258235

In contrast to amino acids with a bulky substituent like tert-leucine, adamantylglycine has so far received little attention. Here, a new, practical synthesis of adamantylglycine is described. This is based on a highly diastereoselective addition of adamantyl Grignard reagent to 2,3-O-cyclohexylideneglyceraldehyde N-benzylnitrone, mediated by the Lewis acid diethylaluminum chloride. Adamantylglycine is obtained from the nitrone in 6 steps and 28% yield as a crystalline hydrochloride with 0.5 methanol incorporated.