(E)-6-(Bromomethylene)-3-(1-naphthalenyl)tetrahydro-2H-pyran-2-one (E)-6-(Bromomethylene)tetrahydro-3-(1-naphthalenyl)-2H-Pyran-2-one 2H-Pyran-2-one, 6-(bromomethylene)tetrahydro-3-(1-naphthalenyl)-, (E)- 6-(Bromomethylene)tetrahydro-3-(1-naphthaleneyl)-2H-pyran-2-one 6-Btnpo 88070-98-8 Bromoenol lactone HELSS