Synthesis of the anti-virus compound shuangkangsu's analogs.

Four novel cyclic peroxide glucosides 15a, 15b, 16a, and 16b, optically pure analogs of shuangkangsu (1), which is an anti-virus natural product with an unusual skeleton isolated from the buds of Lonicera japonica Thunb, were first synthesized totally in six steps including cycloaddition of furan with diethyl acetylenedicarboxylate and glycosylation.