Cycloaddn. reactions of thiete 1,1-dioxide (I) with 3 benzonitrile oxides, PhCH:N(O)Me (II), and 5,5-dimethyl-1-pyrroline N-oxide, and of trans-MeCH:CHSO2Ph (III) with PhCNO and II were studied exptl. The regiochem. of the cycloaddns. of I and III was markedly different. The charge-transfer stabilization energy, calcd. by the method of L. Salem and G. Klopman (1968) in the CNDO/2 approxn., accounts for the trends of the isomer ratios of these and previously studied related reactions of nitrones and diazo alkanes. An anal. of the calcns. performed for cis-syn-vinyl sulfones explains the change of regiochem. in the reactions of I as due to its blocked cis-syn structure. Unsuccessful predictions obtained with the frontier MO approxn. are discussed.
Experimental and theoretical investigation on the cycloadditions of nitrile oxides, nitrones, and diazoalkanes with acyclic vinyl sulfones and thiete 1,1-dioxide
QUARTIERI, Simona;
1982-01-01
Abstract
Cycloaddn. reactions of thiete 1,1-dioxide (I) with 3 benzonitrile oxides, PhCH:N(O)Me (II), and 5,5-dimethyl-1-pyrroline N-oxide, and of trans-MeCH:CHSO2Ph (III) with PhCNO and II were studied exptl. The regiochem. of the cycloaddns. of I and III was markedly different. The charge-transfer stabilization energy, calcd. by the method of L. Salem and G. Klopman (1968) in the CNDO/2 approxn., accounts for the trends of the isomer ratios of these and previously studied related reactions of nitrones and diazo alkanes. An anal. of the calcns. performed for cis-syn-vinyl sulfones explains the change of regiochem. in the reactions of I as due to its blocked cis-syn structure. Unsuccessful predictions obtained with the frontier MO approxn. are discussed.Pubblicazioni consigliate
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