Synthesis of substituted-(l)-tryptophanols from an enantiomerically pure aziridine-2-methanol.

Enantiomerically pure (l)-tryptophanol (5) was synthesized from 4(R)-iodomethyl-2-oxazolidinone (2) and indolylmagnesium bromide in three steps (52% overall yield). Using this procedure, we also prepared various tryptophanols with substituent(s) on the indole ring. Furthermore, optically active 4(R)-iodomethyl-2-oxazolidinone was readily prepared from an enantiomerically pure aziridine-2(S)-methanol in high yield. [reaction: see text]

Synthesis and antibacterial activity of 2alpha-functionalized 1beta-methylcarbapenems related to KR-21012.

The 2alpha-functionalized 1beta-methylcarbapenems 3 were synthesized from the 2-formyl 1beta-methylcarbapenem intermediate 5. The best compound in the series of 2alpha-(hydroxy)alkylcarbapenems, KR-21012, displayed well balanced in vitro and in vivo activity as a parent compound of oral carbapenem.