SYNTHESIS OF THE 1,2'-1',2-DIANHYDRIDE OF 3,4-DI-O-ACETYL-BETA-L-RHAMNOPYRANOSE AND METHYL 3,4-DI-O-ACETYL-ALPHA-D-GALACTOPYRANURONATE FROM "2-O-(ALPHA-D-GALACTOPYRANOSYLURONIC ACID)-L-RHAMNOPYRANOSE

The title compound was synthesized from 2-O-(α-d-galactopyranosyluronic acid)-l-rhamnopyranose (1), showing that the dianhydride is a cyclization product of 1. Formation of the dianhydride reached a maximum within 4 h, in both 2.5 and 5% methanolic hydrogen chloride at 90°. © 1979.