Synthesis of Spiroheterocyclic Cyclohexadienones of Biological Interest

Significance

Starting from dopamine, a route to novel heterocyclic compounds via chemical and enzymatic oxidation of the intermediate ortho-benzoquinone is reported. In the case of trichloroacetimidine (1), the reaction provides an unusual example for the formation of a stable spirocyclic product 2, while ortho-benzoquinone-substituted thiourea 3 cyclizes to a new benzo[d][1,3]thio­azepine 4.