Toddalenone: a new coumarin from Toddalia asiatica (T. aculeata) structural establishment based on the chemical conversion of limettin into toddalenone

Toddalenone, a new coumarin, was isolated from Toddalia asiatica (L.) Lam. (T. aculeata Pers.). Its structure was established as the formula (1) by correlation with limettin (2). Vilsmeier-Haack formylation of limettin (2) gave 8-formyllimettin (10) in good yield. Aldol condensation of this material (10) with acetone afforded toddalenone (1).