Diaroyl furoxans

Aroylnitrile oxides can also be generated from diaroyl furoxans 183 under micro-wave irradiation [33]. Formation of the nitrile oxide intermediate 184 and its cycloaddition with dipolarophiles proceeds at atmospheric pressure within minutes in the absence of solvent and in good yields (Scheme 9.56). The reaction occurs by the rear-... 

Occurs at higher frequency in strained furoxans.76 b In diaryl and diaroyl furoxans and their derivatives. 

Furoxans, bis[(acetoxyalkyl)carbonyl]-synthesis, 6, 421 Furoxans, bisarylsulfonyl-synthesis, 6, 423 Furoxans, bis(dialkylamino)-synthesis, 6, 414 Furoxans, butylhexynyl-synthesis, 6, 423 Furoxans, decamethylenering cleavage, 6, 405 Furoxans, diacyl-thermolysis, 6, 81 synthesis, 6, 442 Furoxans, diadamant-1-yl-ring cleavage, 6, 404 Furoxans, dialkoxycarbonyl-synthesis, 6, 423 Furoxans, dialkyl-synthesis, 6, 423 Furoxans, diaryl-ozonolysis, 6, 405 Furoxans, diaroyl-isoxazoles from, 6, 82 Furoxans, dibenzoyl-synthesis, 6, 423 Furoxans, diethoxycarbonyl-synthesis, 6, 423... 

Diaryl- (85), diaroyl- (71), bis(4-substituted-l,2,5-oxadiazol-3-yl)furoxans (104) as well as exotic l,2,2,5,5-pentamethyl-4-(nitromethyl)-3-imidazoline 3-oxide-derived furoxan 22 (105) were obtained via corresponding nitrile oxides. 

Diacetylfuroxan, which is described in the older literature as an unstable oil,172 is considerably more stable when obtained in a reasonably pure state, e.g., prepared as described by Peterson.173 It is nevertheless prone to explode on distillation. Two dioximes of this compound are also known.486 Apart from the diaroyl compounds, few other diacylfuroxans have been reported.183,214,240,368 The dialdehyde is produced by nitrous acid deoxi-mation of a-isocyanilic acid (144).487 Otherwise, aldehydes in the furoxan series are unknown. The 3-aldoxime (127) has been found among the fulmi-nuric acid derivatives.371... 

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