ADDITION OF AZOLES AND AMINES TO UNSYMMETRICAL FUMARIC ESTERS

The regioselectivity of nucleophilic addition of azoles to unsymmetric al fumarates yielding the corresponding (+/-)-2-azol-1-ylsuccinates ha s been studied, The major regioisomer has been identified as the one o btained from the attack of the azole to the more congestive side of th e double bond. These results have been interpreted in terms of HOMO-LU MO interactions using semiempirical AM1 molecular orbital calculations , Addition of amines as alternative heteronucleophiles has been also e xplored to confirm the regioselectivity. Neutral hydrolysis of the two n-butyl ethyl (+/-)-2-imidazol-1-ylsuccinate regioisomers 8a and 8b h as shown that this hydrolysis takes place faster than with the corresp onding symmetrical di-n-butyl (+/-)-2-imidazol-1-ylsuccinate, and the apparent rate of hydrolysis is independent of the size of the alcohol moiety.