First synthesis of N-indigoglycosides -: Analogues of cancerostatic akashines

The first and surprisingly simple synthesis of N-indigoglycosides has been accomplished based on glycosylation of N-benzylindigo with tri-O-pivaloyl-alpha-L-rhamnosyl trichloroacetimidate and subsequent rearrangement of the O- into the N-glycoside. N-Indigoglycosides are of considerable pharmacological relevance and occur in cancerostatic natural akashines.