Phyllanthostatin 1-Phyllanthoside Orthoacid Rearrangement

Article abstract of DOI:10.1021/jo00225a012

Solvolysis of phyllanthoside (1b) in 1:9 ethanol-water (14 days at room temperature) consumed about 54percent of the starting glycoside and afforded the S3'-monoacetyl derivative 1f and phyllanthostatins 1 (1a) and 4 (1e) in 8-10percent yields accompanied by five related products of orthoacid rearrangement and/or deacetylation.Several additional minor transformation products were detected by HPLC analyses.When phyllathostatin 1 (1a) was subjected to the same solvolysis reaction for 21.5 h, approximately half rearranged to phyllanthoside (1b).After 4 days the product composition resembled that from phyllanthoside.Discovery of the phyllanthostatin 1 <*> phyllanthoside orthoacid rearrangement revealed a very important aspect of Phyllanthus glycoside chemistry and provided the first examples of O-3 <*> O-4 acetyl migrations in a glucopyranoside.