1-Benzyloxy-3-(p-tolylsulfonyl)propene as an acrolein β-anion equivalent. Synthesis of 4-substituted 2-butenolides

Article abstract of DOI:10.1016/S0040-4039(00)60211-3

Lithiation of 1-benzyloxy-3-(p-tolylsulfonyl)propene 6 and reaction with aldehydes give alcohols 7. Sequential hydrolysis-cyclization, oxidation and DBU-mediated elimination of dine elements of p-TolSO₂H gives 4-substituted 2-butenolides 10 in good overall yield.