Rearrangement of dithianylcyclobutachromanol derivatives to 1,2,2a,8,9,9a-hexahydrocyclobuta[b][1]benzoxepin-8,9-dione
Abstract
A novel rearrangement of dithianylcyclobutachromanol derivative 3a on treatment with mercuric oxide and fluoroboric acid in aqueous tetrahydrofuran leads to 1,2,2a,8,9,9a-hexahydro-2a,9a-dimethylcyclobuta[b]-[1]benzoxepin-8,9-dione whose structure is established by X-ray analysis.