Selinane

Laurencia) collected in Australia and California. " This compound represents the first naturally occurring brominated sesquiterpenoid belonging to the eudes-mane (selinane) group. 

Brennan, M. R. and Erickson, K. L. (1982) Austradiol acetate and austradiol diacetate, 4,6-dihydroxy-(+)-selinane derivatives from an Australian Laurencia sp. J. Org. Chem. 47, 3917-3921. 

I selinane derivative. These products are the only known isovetivane derivatives. This framework was originally assigned erroneously to natural products shown Ubsequently to be spiranes. 

Eudesmanes (selinanes). Bicyclic sesquiterpenes with 7-isopropyl-1,4a-dimethyldecalin skeleton. 

Carbon atoms C-1 and C-10 in addition to C-2 and C-7 of famesane link up to close the eudesmane bicyclic skeleton of sesquiterpenes with trawj-decalin as core structure with corresponding numbering of the ring positions. To date, about 500 eudesmanes, formerly referred to as selinanes, have been documented in the litera-... 

Sceletium alkaloid A4, K20 Schellhammericine, K7 Schellhammeridine, K7 Schellhammerine, K7 Scillarenin, T49 Sclareol, T34 Sclerotiorins, Yll Scopolamine, K28 Secodaphniphylline, K26 Secoisolariciresinol, Y7 Secologanin, T13 Securinine, K18 Sedamine, K18 Sedridine, K19 Selenium compounds, A18 Selinane, T19 Selinenes, T19 Semi-a-carotene, T54 Senecic acid, K23 Seneciphyllic acid, K23 Seneol, Y19 Senepoxide, Y19 Sequirins, Y9 Serine, A4 Serpentine, K9 Serratenolone, T44 Serratidine, K25 Serratinidine, K25 Serratinine, K25 Serratine, K25 Sesquicarene, T6 Sesquiphellandrene, T2 Sesquiterpenes, T16-32 Sesterterpenes, T41... 

Structure of (335) for a-helmiscapene was confirmed by formation of (+)-5-selinene (329) from (335) and by comparison of the CD curve of (335) with that of the C-7 epimer obtained from santonin. The structure of (3-helmiscapene (336) was assigned from its C-NMR spectrum and the formation of cw-selinanes, identical with the tetrahydro derivatives obtained from (335) (Scheme 39) (2). 

The junction of the two cyclohexanes is trans for eudesmanes and cIs for selinanes Figure13.14 Biogenesis of the sesquiterpenes of LoufEnc/o-3 (Erickson, 1983). 

Kazlauskas, R., Miuphy, P.T., Wells, R.J., Daly, J.J., and Oberhansli, W. E. (1977a) Heterocladol, a halogenated selinane sesquiterpene of biosynthetic significance from Laurencia filiformis, its isolation, crystal structure and absolute configuration. Aust. J. Chem., 30, 2679-2687. 

Very few halogenated sesquiterpenes have been isolated from brown algae. The Dictyotale Padina tetrastromatica is the first example of a Phaeophyceae in which halogenated sesquiterpenes have been found, although it is actually nor-sesquiterpenes, which could come from the oxidation of perhydrohnalool (Parameswaran et al., 1994). Recently, two brominated selinane sesquiterpenes have been characterized in Dictyopteris divaricata from China (Ji et al, 2009). 

There are few representatives of elemane and nor-elemnane carbon skeletons, but there are many examples of its diterpenic isoprenolog, known imder the name lobane (see below). The carbon skeletons of eudesmane and selinane differ only in the stereochemistry of the jimction between the two cyclohexanes. Currently, derivatives of eudesmane seem characteristic of Alcyonacea, and those of sebnane characteristic of Stolonifera, although for the latter the published results relate only to the spedes Tubipora musica (blue coral). 

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