Figure 1

Photooxygenation of 1 to produce volatile compounds (2–5). Tricyclic triterpene, (+)-ambrein (1), is the primary source of ambergris-derived odor components^{2,3,4,9,10,11}. Photooxidative degradation of 1 by¹O₂ around its central double bond produces volatile compounds with smaller molecular weights^{2,3,4,9,10,11}. 2-5 are the main components identified. Tricyclic volatiles 3–5 originate from the bicyclic part of 1, while the smaller fragment 2 is related to the monocyclic part of 1^{2,3,4,9,10,11}.