New information regarding the transformations of furans under nitration conditions. Direct oxidative cleavage of 2-cyclopropyl- and 5-methyl-2-cyclopropylfurans by means of a nitrating agent
The principal pathway of the reaction of 2-cyclopropylfurans with acetyl nitrate in acetic anhydride or with nitrogen tetroxide in methylene chloride is cleavage of the furan ring with the formation of unsaturated 1,4-dicarbonyl compounds. Nitro-furylcyclopropanes are formed in low yields via an independent pathway under these conditions. The possible pathways of nonhydrolytic cleavage of the furan ring under anhydrous nitration conditions are discussed.