Under acidic conditions dihydromancunine (2) can be obtained directly from 3β-dihydrovincoside (1c) by cyclisation of N-4 to C-21, whereas 3α-strictosidine (1a) affords a novel N-1 cyclised derivative, nacycline (6).
在酸性条件下dihydromancunine(2)可以直接从3β-dihydrovincoside(获得1C)由N-4至C-21的环化,而3 α -strictosidine(1A),得到一种新颖的N-1环化衍
生物,nacycline(6) 。