Phthalides special

The essential oil of celery, for example, contains 3-butyl-phthalide (63), 3-butyl-hexahydro-phthalide (64) as well as sedanolide (65) (705). The latter two lactones (64) and (65) have the characteristic odor and flavor of celery (705). Reports on the occurrence and importance of this class of aroma compounds are to be found in specialized review articles (795, 354). 

---