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The cycloaddition reactions of several phenylsulfonyl-substituted allenes with diazomethane have been investigated. The major products formed were identified as 3-(phenylsulfonyl)-4-methylene-2-pyrazolines. These pyrazolines engage in a variety of mechanistically interesting transformations, ranging from base-catalyzed rearrangements to addition of Grignard regents. The dipolar cycloadduct derived from the reaction of diazomethane with 3-(phenylsulfonyl)-1,2-butadiene undergoes a 1,3-phenylsulfonyl shift upon irradiation to give 3-methyl-4-[(phenylsulfonyl)methyl] pyrazole. The cycloadduct derived from the reaction of 2,3-bis(phenylsulfonyl)-1-propene with diazomethane readily loses nitrogen upon photolysis to give 1-[(phenylsulfonyl)methyl]-1-(phenylsulfonyl)cyclopropane

Le traitement du 2,3-dibromo-1-benzenesulfonyl-1-propene avec des composes β-dicarbonyles en presence de methoxyde de sodium conduit avec un haut rendement au furane bicyclique 2,4-disubstitue et au furane bicyclique 2,3-fusionne. La formation du cycle furane implique une sequence d'addition-elimination, une deacetylation et des reactions de deplacement de type SN2

Les cycloadditions dipolaires 1,3 de l'[arylidene hydroxytrimethylsilyl] ammonium (A) sont etudiees. Selon la nature du dipolarophile, (A) se comporte soit comme une nitrone soit comme un ylure d'ammoniomethanure