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‐2 H ‐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)