Synthesis of cis-substituted .BETA.-lactams, potential intermediates for cis-carbapenems, from L-aspartic acid.
作者:YOSHIO TAKAHASHI、SHIGERU HASEGAWA、TOSHIO IZAWA、SUSUMU KOBAYASHI、MASAJI OHNO
DOI:10.1248/cpb.34.3020
日期:——
(3S)-3-Benzyloxycarbonylamino-γ-butyrolactone was prepared by the regioselective reduction of L-aspartic acid. Alkylation and aldol condensation of the γ-butyrolactone afforded the trans isomer selectively. The resulting 2, 3-trans γ-butyrolactone was hydrolyzed and then cyclized to give the 3, 4-cis β-lactam. By taking advantage of this strategy, key intermediates of epi-PS-5 and carpetimycins were synthesized.
(3S)-3-苄氧基羰基氨基-γ-丁内酯是通过L-天冬氨酸的区域选择性还原制备的。 γ-丁内酯的烷基化和羟醛缩合选择性地提供反式异构体。将所得2, 3-反式γ-丁内酯水解,然后环化得到3, 4-顺式β-内酰胺。利用这一策略,合成了epi-PS-5和地毯霉素的关键中间体。