A facile and convenient synthesis of tetrasubstitutedN-hydroxypyrroles via intramolecular wittig reaction

Treatment of triphenylphosphine with dialkyl acetylenedicarboxylate leads to 1:1 adduct and concomitant protonation of late adduct by pentan-2,3,4-trione 3-oxime gave the reactive intermediate, vinyltriphenylphosphonium salts, which undergoes an intramolecular Wittig reaction to produce tetrasubstituted N-hydroxypyrroles in fairly high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:100–103, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20382