Hinckdentine A is an alkaloid isolated from the bryozoan Hincksinoflustra denticulate. This natural product contains a novel and unique 11b,12,13,14,15,16-hexahydroazepino[4',5':2,3]indolo[1,2-c]quinazoline ring system that has not previously been synthesized. We have synthesized 8-desbromohinckdentine A from a 2-aryl indole by first preparing the quaternary center of the natural product and then building the seven-membered lactam and dihydropyrimidine rings onto this intermediate to form the framework of hinckdentine A.

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N-Methyl-N-[(1S)-1-[(3R)-pyrrolidin-3-yl]ethyl]amine (1)(1) is a key intermediate in the preparation of premafloxacin (2), which was under development as an antibiotic for use against pathogens of veterinary importance. This paper describes the development of a practical, efficient, and stereoselective process for the preparation of 1 from isobutyl (3S)-3-[methyl[(1S)-1-phenylethyl]amino]butanoate (5c). The key steps in the synthetic sequence are an asymmetric Michael addition, which yields 5c, and a stereoselective alkylation, which yields (3S,4S)-3-allyl-1,4-dimethylazetidin-2-one (17).

Total synthesis of an antibiotic Andrimid was accomplished stereospecifically; it was shown that the chiralities at C-3 and C-4 should be R and S, respectively, and the presence of the (4S)-methyl group is important for the activity.Andrimid,' a peptide-like antibiotic isolated from the culture broth of an Enterobactor sp.2 intracellular symbiont of the Brown Planthopper, Nilaparvata lugens, exhibits potent activity against Xanthomonas campestris pv. oryzae, the pathogen causing bacterial blight in rice plants. The antimicrobial spectrum of Andrimid is very specific; among phytopathogens so far tested,3 3 Agrobacterium, 4 Corynebacterium, 9 Erwinia, 34 Pseudomonas, and 21 Xanthomonas bacteria