UNSYMMETRICALLY SUBSTITUTED FUROXANTS .17. STRUCTURAL INVESTIGATIONS IN BENZENESULFONYLFUROXAN DERIVATIVES AND RELATED-COMPOUNDS

The reaction of bis(benzenesulfonyl)furoxan 1 with alcohols and thioal cohols in basic medium affords a number of benzenesulfonylfuroxans alk oxy and thioalkoxy substituted, an interesting class of NO-donors. For these derivatives a paramount problem is to locate the position (3- o r 4-) of the substituent to the furoxan ring. In this paper we assign the structure to a number of these derivatives on the basis of both ch emical and NMR evidence. In particular, C-13 NMR substituent constants (A(ik)) were obtained by NMR study of suitable furoxan models. By ass uming a complete additivity of the substituent effects at the furoxan ring, A(ik) values were used for structural determination.