Norlactarane sesquiterpenes

The structurally interesting compounds 15.1 and 15.2 are the only known examples of this class. The molecules have a plane of symmetry and 

Compound 15.2 is a minor product of preparative autoxidation of isovelleral (6.2) 62). 

Molecular mechanics calculations (MM2) (9), in addition to H-NMR data, proved that for all the related sesquiterpenes 10.2, 10.10, 10.13, 16.2, and 16.8 a single conformation of the cycloheptadiene ring is practically the only one however, the geometry of the global minima 

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Norlactarane sesquiterpene 15.1 is considered to be biosyntheti-cally related to oc,P-epoxyketone 11.2, and it has been suggested that expulsion of the C-8 carbonyl group from the lactarane skeleton occurs via a benzylic-like rearrangement, followed by a decarboxylative aromatization (92) (Scheme 5). 

Bosetti, a., G. Fronza, G. Vidari, and P. Vita-Finzi Norlactarane and Lactarane Sesquiterpenes from Lactarius scrobiculatus. Phytochemistry, 28, 1427 (1989). 

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