Synthesis of perfragilin A, B and some analogues

Synthesis of the cytotoxic isoquinoline quinone perfragilin A, an improved synthesis of perfragilin B and preparation of some analogues of both these compounds are described. Cytotoxicity evaluation of a number of the products is reported. The regioselectivity in Diels–Alder reactions of differently substituted benzoquinones with 2-aza-1,3-bis(t-butyldimethylsilyloxy)-1,3-butadiene is described.