A New One‐Pot Synthetic Approach to the Highly Functionalized (Z)‐2‐(Buta‐1,3‐dienyl)phenols and 2‐Methyl‐2H‐chromenes: Use of Amine, Ruthenium and Base‐Catalysis.

A practical and simple one-pot multi-catalysis process for the synthesis of highly substituted benzo[b]oxepines 5, (Z)-2-(buta-1,3-dienyl)phenols 6 and 2-methyl-2H-chromenes 7 from simple starting materials was achieved for the first time through ring-closing metathesis/base-induced ring opening/[1,7]-sigmatropic hydrogen shift reactions. The synthesis of privileged (Z)-2-(buta-1,3-dienyl)phenols 6 via base-induced ring opening of highly functionalized benzo[b]oxepines 5 is described(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)