OCCURRENCE OF β-DOLABRIN (4-ISOPROPENYLTROPOLONE) IN WESTERN RED CEDAR (THUJA PLICATA DONN.)

Abstract
The steam-volatile oil of western red cedar contains traces of a fifth tropolone, β-dolabrin (4-isopropenyltropolone), in addition to α-, β-, and γ-thujaplicin and 7-hydroxy-4-isopropyltropolone. The presence of β-dolabrin, previously obtained from Japanese "Hiba" wood by Nozoe, was detected by paper chromatography and proved by isolation of a sample from the steam-volatile oil by a combination of sodium salt precipitation, fractional crystallization, and preparative paper chromatography. The approximate composition of the steam-volatile oil from butt heartwood is given.