The biomimetic totalsynthesis of potential anti-HIV (−)-isatisine A, a novel alkaloid with an unprecedented fused tetracyclic skeleton, was accomplished in eight steps from indole and known 4,6-O-isopropylidene-protected glucal. The synthetic strategy was inspired primarily by the proposed biogenetic hypothesis that indole C-furanoside would be derived from indole C-glucoside via a ring contractive