Cuminic aldehyde (p-isopropyl benzaldehyde, cuminol) has been observed repeatedly in volatile oils. It is the principal constituent of oil of cumin and has also been found in the oils of boldo leaves, Ceylon cinnamon, myrrh, cassie blossoms, Eucalyptus haemastoma, E. hemiphloia, E. odorata, E. oleosa, E. populi-fera, and water hemlock.

Cuminic aldehyde purified through the acid sulphite addition product has the following properties:

Sp.gr. 235,5°; d15o 0,9818; aD±0°;1) b. p. 232° (760 mm.), 109,5° (13,5 mm.);2) d13o 0.972.3)

) Journ. chem. Soc. 69 (1896), 1199.

2) Anschutz and Reitter, Die Destination unter vermindertem Druck. p. 73.

3) Kopp, Liebig's Annalen 94 (1855), 319.

The semicarbazone of cuminic aldehyde melts at 210 to 211°, the phenyl hydrazone at 126 to 127°, the oxime at 58 to 59°. Upon oxidation it yields cuminic acid which melts at 115o.