Pentaoxygenated berbines: Total synthesis of (±) O-methylcapauridine and (±) 0, 0'-dimethylstephabinamine

R S Mali, Y T Bodkhe, N V Gulati

Abstract


A convenient total synthesis of pentaoxygenated berbine alkaloids; (2)-0-methylcapauridine(lSa), (+) 0,O'- dimerhylstephabinamine(15c) and a berbine(15b) is described from 3,4,5-trimethoxy-6-phenylethylamine( mescaline 12). Condensation of mescaline (12) with isochroman-3-ones (13a-c) in refluxing ethanol gives hydrony amides (14a-c) which an Bischler-Napieralski cyclisation with POCl3 in reflulxmg toluene, followed by NaBH4 reduction, provides the berbine alkaloids Ha, Uc and berbine 15b.

Keywords


Heteroatom-directed hthiation reaction; Bischler-Napieralski cyclisation; mescaline; isochroman-3- ones; berbine alkaloids.

Full Text:

PDF

Refbacks

  • There are currently no refbacks.