Stereoselective synthesis of yohimbine alkaloids from secologanin
作者:Richard T. Brown、Simon B. Pratt
DOI:10.1039/c39800000165
日期:——
Glucolysis of methyl secoxyloganin (3) at pH 7 has afforded, via a biogenetically patterned vinylogous aldol reaction, two key substituted cyclohexenes (6) from which the acetates of β-yohimbine (10a), yohimbine (10b), and their 19,20-dehydro derivatives (9) have been synthesised in addition to dihydrogambirtannine (11) induced to undergo selectively an alternative rearrangement leading to a carbocyclic
Biomimetic synthesis of yohimbine and heteroyohimbine alkaloids from 4,21-dehydrogeissoschizine
作者:C. Kan-Fan、H.-P. Husson
DOI:10.1016/s0040-4039(00)92746-1
日期:——
The first biomimeticsynthesis of the yohimbine skeleton (7) from a Corynanthé-type precursor (2) is reported as well as the transformation of the latter into both the 19R and 19S heteroyohimbine series. Reactions were performed on an alumina surface.