Neotame, an alkylated dipeptide and high intensity sweetener

The title compound, N-[N-(3,3-dimethylbutyl)-L-alpha-aspartyl]-L-phenylalan ine 1-methyl ester (neotame) hydrate, C20H30N2O5. H2O, is an alkylated dipe ptide, The zwitterionic structure, i.e. 3-(3,4-dimethylbutylammonio)-3-[N-( 1-methoxycarbonyl-2-phenylethyl)aminocarbonyl]propanoate hydrate, in the so lid state fits the 'L-shaped' topochemical structure proposed for the requi rement of sweetness ability for aspartyl-based dipeptide compounds. The str ucture suggests that the extraordinary potency of neotame is due to the hyd rophobic positioning of the alkyl and phenyl groups within the molecule, In this crystalline form, obtained from ethyl acetate/hexane, a single water molecule is also present in the unit cell, linked by hydrogen bonds to an a spartate O atom and the methyl ester carbonyl group.