Sesquiterpenoids alcohols

Hu L, Zhongliang CH. Sesquiterpenoid alcohols from Chrysanthemum morifolium. Phytochemistry 1997 44 1287-1290. 

The first enantioselective total synthesis of (-)-myltaylenol was achieved in the laboratory of E. Winterfeldt. The authors used an intramolecular Diels-Alder cycloaddition and the Shapiro reaction as key transformations to construct the unusual carbon framework of this sesquiterpenoid alcohol natural product, which contains three consecutive quaternary carbon atoms. 

Typically, the oil will contain 45-47% of the a-isomer and 20-30% of the (3-isomer. Both isomers contribute to the distinctive woody odour of the oil. The (3-isomer is more intense and also contributes to the slightly animalic, urinous character of the oil. It is interesting to note that the odours of sandalwood and urine are closely related. One of the commonest parosmias (where an odorant is perceived differently by different subjects) is that of sandalwood and urine. Similarly, when a secondary alcohol with a sandalwood character is oxidised to the corresponding ketone, there is a high probability that the ketone will smell urinous. There are many other components in sandalwood oil, particularly sesquiterpenoids alcohols, aldehydes and hydrocarbons. Some of these make important contributions to the overall odour effect. 

Sun, H. H., S. M. Waraszkiewicz, and K. L. Erickson Sesquiterpenoid Alcohols from the Hawaiian Marine Alga Laurencia nidifica — III. Tetrahedron Letters 1976, 585. 

Connolly ID, Harrison LJ, Rycroft DS 1984 The structure of tamariscol, a new pacifigorgiane sesquiterpenoid alcohol from the liverwort Frullania tamarisci. Tetra Lett 25 1401-1402... 

The sesquiterpenoid hydrocarbons (5)-a-curcumene (59) and (5)-xanthorrhizol (60) were prepared by asymmetric conjugate addition of the appropriate aryllithium reagent to unsaturated oxazoline 56 to afford alcohols 57 (66% yield, 96% ee) and 58 (57% yield, 96% ee) upon hydrolysis and reduction. The chiral alcohols were subsequently converted to the desired natural products. ... 

The antipodal relationship appears secure despite differences in the magnitude of the rotation values ([a]D 32, —63° 43, +100°), both of which were measured in CC14. Of particular interest is the isothiocyanato-alcohol 46, which is the first example of an oxygenated marine sesquiterpenoid possessing a function unrelated to the -NC/-NCS/-NHCHO triad. 

The result obtained by GC-MS, with the same SPME conditions, from the black thick balm of a crocodile mummy (sample 1400, Musee Guimet, Lyon, France) is presented in Figure 10.11. The composition of the extract is close to that of sample 1998 but phenolic compounds were not detected. The GC-MS chromatogram obtained with the same substance after acid methanolysis and silylation is presented in Figure 10.12. Except for the sesquiterpenoids eluted between 10 min and 22 min, the observed compounds originate from a beeswax. The biomarkers of this substance are hexadecanoic acids hydroxylated in position 14 or 15 and long chain hydrocarbons, acids and alcohols eluted between 50 min and 90 min. Diterpenoid or triterpenoid resin components are not observed. 

A. F. Thomas, M. Ozainne, New sesquiterpene alcohols from galbanum resin the occurrence of C (10) epi sesquiterpenoids, Helv. Chim. Acta, 61(8), 2874 2880 (1978). 

G.l.c. papers of interest include the classification of 22 acyclic monoterpenoid alcohols according to retention indexes, resolution of cyclic ketones [e.g. ( )-menthone, ( )-isomenthone] as diethyl (+)-tartrate acetals, and the use of lanthanide shift reagents to resolve non-terpenoid racemic epoxides.The occurrence and prevention of monoterpenoid hydrocarbon isomerization during silica gel chromatography has been examined and the separation of monoterpenoids and sesquiterpenoids by gel permeation chromatography is reported. Monoterpenoid hydrocarbons have been selectively extracted from essential oils using dimethylsilicone. ... 

East Indian sandalwood oil consists almost exclusively of closely related sesquiterpenoids by far the main constituents are the alcohols a-santalol [115-71-9], 45-55%, and /3-santalol [77-42-9], 18-24%. Mainly responsible for the odor is /3-santalol. [261, 764-769]. 

Since 1951, the development of modern methods of separation and identification has made it possible to reexamine some structures that were looked upon as established. Here are a few significant examples. Bisabolangelone (34),91 a sesquiterpenoid hydrobenzofuran alcohol, was initially described as having a furocoumarin structure.92 A phenolic compound, once thought to have the structure of an auronol (35),93,94... 

In order to expand the worldwide market, considerable efforts are being devoted to improve the image of Madeira wine. Consequently, their characteristics have to be well defined. So, in order to define and describe the particular characteristics and the authenticity of the product, secondary metabolites of grape and wines mainly linked to a specific variety, must be deeply studied. In Madeira wine, these compounds are mainly included in the chemical classes of mono and sesquiterpenoids C13 norisoprenoid higher alcohols, ethyl esters, volatile fatty acids, carbonyl compounds, sulfur compounds, furanic compounds, lactones, and polyphenols. 

Sesquiterpenoid Derived from a sesquiterpene but containing a functional group such as an alcohol e.g. bisabolol, called a sesquiterpenol. 

Biosynthetic considerations and the discovery of their co-occurrence with a-cedrene (42) and (+)-zizaene (43) have led to the reformulation of various cedrane derivatives (44 R = Me, CH2OH, CHO, or COzH) found in vetiver oil 76 it is believed that these sesquiterpenoids are formed from the common precursor (45). The metabolites of cedrol found in the urine of rabbits are mainly glucuronides of hydroxylated cedrol derivatives 77 presumably formation of the glucuronide of the tertiary alcohol itself is difficult because of steric hindrance. 

An on-going investigation of the sesquiterpenoids of North Indian vetiver oil has revealed the presence of the three alcohols (569)—(571). ° A new and shorter synthesis of ishwarone (572) has been reported (Scheme 72). ... 

The Ci5 terpenoids known as sesquiterpenoids are the most chemically diverse group of terpenoids known in nature. Like monoterpenoids, many sesquiterpenoids contribute to the flavor and fragrances of a variety of plant products. To date about 10,000 sesquiterpenoids are known (32), and in the plant kingdom they commonly occur as hydrocarbons, alcohols, aldehydes, ketones, carboxylic acids, lactones, and oxiranes. The acyclic sesquiterpene hydrocarbons a- and p-farnesenes (HI and H2, respectively) (Fig. 8) are constituents of the oils... 

In their synthesis of fukinone, Marshall and Cohen converted the known ene-ol (340) into (341) by acetylation, allylic oxidation, and conjugate methylation with dimethylcopperlithium. A Wolff-Kishner reduction of (341) followed by oxidation of the resultant alcohol and enol-acetylation yielded (342). The epoxide of (342) was thermolysed to give (343) which, on reaction with iso-propenyl-lithium and selective oxidation, gave the ketol (344) which was converted in two steps into fukinone (335). A number of sesquiterpenoids, e.g. fukinanolide (345), with the rearranged eremophilane skeleton viz. fukinane (346 R = Me) are known. Nay a and Kobayashi have now prepared this parent hydrocarbon by Raney nickel reduction of the thioacetal of fukinan-8-al (346 R = CHO). 

The mass spectra of a large number of sesquiterpenoids have been published. These consist mainly of hydrocarbons together with a limited number of alcohols and aldehydes. The mass spectra of some furanosesquiterpenoids have also been published. G.l.c. data have been collected for a number of sesquiterpene alcohols and furanosesquiterpenoids. ... 

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