abstract n-(2-bromopropionyl)-o-benzyl-l-serine (bpbs) was prepared using 2-bromopropionic acid
and n-boc-o-bzl-l-serine as the starting reagents. bpbs underwent the intra-molecular ring-closing reac-
tion in dmf/et
3
n solvent at 80 ℃for 9 h forming a mixture of two non-enantiomers, i.e. (3s,6s)-benzyl-
oxymethyl-6-methyl-morpholine-2,5-dione [(3s,6s)-bmmd] and (3s,6r)-bmmd with a yield of 70%. two
optically pure enantiomers of bmmd, i.e. (3s,6s)-bmmd and (3s,6r)-bmmd were obtained via 4 opera-
tion circles of “solution-partial recrystallization” by means of a differential recrystallization method using
ethyl acetate as a solvent. the single crystals of the two isomers of bmmd were grown from ethyl acetate at
room temperature. the fine molecular structures of the two isomers were determined by x-ray diffraction
analysis of the single crystals.
keywords (3s,6s)-benzyloxymethyl-6-methyl-morpholine-2,5-dione; (3s,6r)-benzyloxymethyl-6-methyl-
morpholine-2,5-dione; resolution; optical isomer; crystal structure