A non-catalytic regioselective approach to the synthesis of (E)-stilbenes from suitably functionalized 2H-pyran-2-ones

Highly functionalized (E)-stilbenes 3a–m and 4-aryl-6-styryl-pyran-2-ylidineacetonitriles 4a–b have been prepared and delineated through the ring transformation of 6-aryl-3,4-disubstituted-2H-pyran-2-ones 1 with commercially available (E/Z)-4-phenyl-3-buten-2-one 2 without the use of any catalyst.