Regioselective cyclization of α,ω-alkynoic acids catalysed by TpRu complexes: synthesis of endocyclic enollactones [Tp = hydrotris(pyrazolyl)borate]Electronic supplementary information available: selected spectral data for enol lactone derivatives. See http://www.rsc.org/suppdata/cc/b1/b106647c/
Abstract
The σ-enynyl complex [TpRu{C(Ph)C(Ph)C
CPh}(PMeiPr2 )] efficiently catalyses the regioselective cyclization of α,ω-alkynoic acids to yield endocyclic