Chemical Syntheses of Biosynthetic Intermediates

Works concerning the chemical synthesis of intermediates along the ajma-line (1) biosynthesis pathway, as significant as parts of alkaloid biosynthesis research, were also mentioned here. 

Elegant chemical synthesis of geissoschizine (46) and geissoschizine-type derivatives which are important for early steps in Rauvolfia alkaloid biosynthesis, have been reported decades ago by Winterfeldt and coworkers. 

First enantiospecific total syntheses of biogenetic intermediates on the way to sarpagine (5), such as polyneuridine aldehyde (46) or 16-epi-vellosimine (49), have been reported recently by Cook and coworkers. For most recent publications see Refs 43,44. 

A very interesting enantioselectively synthetic approach to sarpagine alkaloids, developed very recently by Gaich and coworkers needs to be mentioned here. For a review in this field see Ref 46. 

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