反应详情

Condensation of (S)-2-[benzyloxycarbonyl-(2-oxo-ethyl)-amino]-propionic acid methyl ester (intermediate 1) with (S)-2-amino-butane-1,4-diol in analogy with examples 1/2F produced a nearly statistical mixture of the title compound [light yellow gum, MS: 335.5 (M+H)+] and (4S,7S)-4-hydroxymethyl-7-methyl-6-oxo-hexahydro-pyrazino[2,1-b][1,3]oxazine-8-carboxylic acid benzyl ester [light yellow gum, MS: 335.4 (M+H)|], which were separated by column chromatography (SiO2; DCM→DCM/MeOH/25% aq. ammonia solution 90:10:0.25).

1. customproduced