反应详情

A mixture of 70 mg (0.32 mmol) of trans-1,2-diacetoxy-1,2-dihydrobenzocyclobutene and 66 mg (0.21 mmol) of methyl rac-1',2',3',4',5',8'-hexahydro-5',8'-dioxospiro[1,3-dithiolane-2,4'-naphthalene]-2'-carboxylate [prepared as described in Example 2(A)] in 5 ml of xylene was stirred and heated under reflux under an atmosphere of nitrogen for 23 hours. The mixture was evaporated to dryness and the residue was stirred with 5 ml of diethyl ether and then filtered to give 52 mg (60%) of methyl rac-1',2',3',4',5',12'-hexahydro-5',12'-dioxospiro[1,3-dithiolane-2,4'-naphthacene]-2'-carboxylate in the form of a bright yellow solid of melting point 216° C.

1. temperatureheated
2. temperatureunder reflux under an atmosphere of nitrogen for 23 hours
3. customThe mixture was evaporated to dryness
4. stirringthe residue was stirred with 5 ml of diethyl ether
5. filtrationfiltered