Biomimetic Synthesis of Thiaplidiaquinones A and B

A biomimetic synthesis of the biologically active ascidian metabolites thiaplidiaquinones A and B is described. Reaction of geranylbenzoquinone with Et3N in CH2Cl2 yielded two isomeric quinones, comprising the benzo[c]chromene-7,10-dione core of the natural products. Subsequent reaction with hypotaurine yielded the title compounds and their dioxothiazino regioisomers.