Precondylocarpine

Sewarine, from Rhazya stricta, was shown to be 10-hydroxyakuammicine (66a) by spectral comparison with akuammicine (66b) and with other a ring oxygenated indole alkaloids. " Preakuammicine (67a), an isomer of precondylocarpine (67b), has been isolated from young Vinca rosea seedlings. " The retroaldol loss of formaldehyde and the formation of akuammicine was base catalysed. Boro-hydride reduction, as well as causing some retroaldolisation, gave rise to stemmadenine (65). 

The structure deduced recently for andranginine (143) on the basis of H and n.m.r. spectra and a partial synthesis from precondylocarpine acetate has been independently confirmed by examination of the H n.m.r. spectrum of andrangininol (144) by the Fourier Transform Difference Spectra method.This technique. 

The first partial synthesis of andranginine (338) was reported by the French group in collaboration with Scott and Wei (125). Thermolysis of precondylocarpine acetate (344) at 100° in ethyl acetate afforded andranginine (338) in 28% yield, again via the didehydrosecodine (339). The other products of the reaction were not discussed at that time. 

Andranginine °" (92) from Craspidospermum verticillatum has a skeleton of an entirely novel type. Its inclusion in this sub-section is based on its partial synthesis from precondylocarpine acetate (93). The evidence so far advanced for the structure is a simple statement of and [given on (92)] n.m.r., u.v.,... 

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