25946-29-6Relevant articles and documents
Identification of m-Mentha-3(8),6-diene (isosylveterpinolene) in black pepper oil
Nussbaumer, Cornelius,Cadalbert, Riccardo,Kraft, Philip
, p. 53 - 58 (1999)
m-Mentha-3(8),6-diene (= isosylveterpinolene; 5), which has not been found in nature before, was shown by GC/MS analysis and co-injection with a synthetic sample to be present to the extent of 0.12-0.17% in black and green pepper oil. The synthetic reference 5 was prepared by deconjugation of 3- methylcyclohex-2-en-1-one (1), subsequent alkylation with lithium 2-lithio- 2-methylpropanoate, and decarboxylative dehydration of the resulting hydroxycarboxylic acid 3 employing dimethylformamide dimethyl acetal. On polar GC columns, 5 was eluted between p-cymene and terpinolene, and was characterized by an MS similar to that of terpinolene, but with the fragment m/z 121 (59, [M - Me]+) being less intense than that of the molecular ion at m/z 136 (67, M+). Since m-mentha-3(8),6-diene was also found to the extent of 0.24% in the headspace of ground black peppercorns, it can be considered to be of genuine natural origin, and thus is the first established example of a naturally occurring m-menthadiene.
