trans-1,2-Diacetoxy-1,2-dihydrobenzocyclobutene → Methyl rac-1',2',3',4',5',5a',6',11',11a',12'-decahydro-6',11'-diacetoxy-5',12'-dioxospiro[1,3-dithiolane-2,4'-naphthacene]-2'-carboxylate

Participants

Reaction Steps

A solution of 0.757 g (3.4 mmol) of trans-1,2-diacetoxy-1,2-dihydrobenzocyclobutene and 0.970 g (3.1 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 100 ml of dry xylene was stirred and heated under reflux under an atmosphere of nitrogen for 1 hour. The mixture was evaporated to dryness and the resulting brown oil was triturated with 10 ml of diethyl ether, cooled and filtered to give 1.02 g (61.5%) of methyl rac-1',2',3',4',5',5a',6',11',11a',12'-decahydro-6',11'-diacetoxy-5',12'-dioxospiro[1,3-dithiolane-2,4'-naphthacene]-2'-carboxylate in the form of a pale yellow solid of melting point 174°-175° C.

Provenance & Evidence