Several acetals of γ-oxo-α,β-unsaturated esters have been prepared, mainly from enantiopure C2-symmetric diols, and their 1,3-dipolar cycloaddition to 2,3,4,5-tetrahydropyridine 1-oxide has been studied. All the reactions showed complete regioselectivity and a high preference for the endo approach of the reactants in the transition state. The enantiopure acetals derived from (cis,cis)-spiro[4.4]nonane-1,6-diol gave the highest diastereofacial selectivity. © 2001 Elsevier Science Ltd. All rights reserved.
|Publication status||Published - 16 Jul 2001|