First Synthesis of Bioactive Diphyllin Glycosides Isolated from Justicia patentiflor Hemsl

The syntheses of three naturally occurring diphyllin glycosides have been achieved. 7‐O‐β‐D‐Quinovopyranosyl‐ diphyllin (patentiflorin A) and 7‐O‐β‐L‐fucopyranosyldiphyllin (patentiflorin B) were synthesized by the glycosylation of diphyllin with peracetylglycosyl bromides under phase transfer catalysis (PTC) conditions. 4"‐O‐Acetyl‐7‐O‐β‐L‐fucopyranosyldiphyllin (4"‐O‐acetyl patentiflorin B) was obtained from patentiflorin B on an orthoesterification‐orthoester rearrangement approach. Their 1H NMR, 13C NMR and HRMS signals are all consistent with those reported for the natural product.