Synthesis of terpenes containing the bicyclo[3.1.1]heptane ring system by the intramolecular [2 + 2] cycloaddition reaction of vinylketenes with alkenes. Preparation of chrysanthenone, .beta.-pinene, .beta.-cis-bergamotene, .beta.-trans-bergamotene, .beta.-copaene, and .beta.-ylangene and lemnalol

Marine natural products

“…~~~ Full details of a second synthesis of ( f )-sinularene have been reported.280 Lemnalol (408), which is an antitumour agent from Lemnalia tenuis,28L has been synthesized by a route that involved an intramolecular [2 + 21 cycloaddition of the ketene that was formed by treatment of farnesoyl chloride with a base. 282 During the mass spawning behaviour of soft corals, the sea becomes so thick with gametes that the eggs can be collected. 3,4-Epoxynephthenol (409), which is the major metabolite of the eggs from Lobophytum microiobulatum, is absent in the post-spawning tissue of the soft Both the eggs and the tissue of the coral contained significant amounts of the isomeric metabolite decaryiol (410) and a new cembranoid, decaryiol acetate (4 1 1).…”

Identification of sesquiterpene synthases from the Basidiomycota Coniophora puteana for the efficient and highly selective β-copaene and cubebol production in E. coli

“…However, another minor product was isolated from the Copu3 fermentation broth. A comparison of NMR spectra to reported references confirmed the presence of β-copaene [ 26 , 27 ], cubebol [ 28 ] and δ-cadinene [ 29 ] as products of Copu2 and Copu3, respectively. Based on the NMR data, we designated Copu2 as a new β-copaene synthase.…”

Monoterpenoids

“…Oxidation of ( + )-trans-verbenol (207) using RuC1,-NaIO,-CCI,-MeCN leads to ( + )-cis-pinononic acid (1 99) in high yield.229 Full details of the synthesis of (*)chrysanthenone (208) from geranyl chloride have been published. 230 Solvolysis of the homoallylic tosylate (209) in AcOH-AcONa yields231 the novel tertiary acetate (210). The derived alcohol (211) is, as might be expected, stable towards acidic conditions.…”

“…Both of the isomeric sabinene hydrates (226) have been obtained from suspension cultures of Ruta graveofens cells. 241 (&)-Sabina ketone (227) has been synthesized via Birch reduction of the phenolic ether (228) to give (229) which was then hydrolysed and hydrochlorinated to yield (230). Ringclosure of (230) to give (227) The diol ( 247) is rapidly and efficiently oxidized to the ketoaldehyde (248) by periodate under two-phase PTC condit i o n ~.…”