Highly oxygenated sesquiterpene

With Tartrate-Derived Chiral 1,4-Diol/Ti Complexes A catalytic asymmetric Diels-Alder reaction is promoted by the use of a chiral titanium catalyst prepared in situ from (Pr O TiC and a tartrate-derived (2.R,3.R)-l,l>4,4-tetraphenyl-2,3-0-(l-phenylethylidene)-l,2,3,4-butanetetrol. This chiral titanium catalyst, developed by Narasaka, has been successfully executed with oxazolidinone derivatives of 3-borylpropenoic acids as P-hydroxy acrylic acid equivalents [40] (Eq. 8A.21). The resulting chiral adduct can be utilized for the first asymmetric total synthesis of a highly oxygenated sesquiterpene, (-i-)-Paniculide. 

The highly oxygenated sesquiterpene paniculide A was synthesized by N. Chida et al. starting from D-glucose. The key step to construct the substituted cyclohexane subunit of the natural product involved the Type II Ferrier rearrangement. 

Paniculide-A is structurally the least complicated of the paniculides, a family of highly oxygenated sesquiterpenes from Andrographis paniculata. Jacobi s synthesis of paniculide-A began with a four-step conversion of 3-methyl glutaric anhydride 175 to the oxazole acetylenic ketone 176 (Fig. 3.54). Cycloaddition of... 

Many sesquiterpenes which are not highly oxygenated are also found in essential oils. Several of these are reported to possess activity. a-Farnesene from apples is an attractant and oviposition stimulant for the codling moth ( ) and farnesol has been demonstrated to be an active feeding deterrent to gypsy moth larvae (Lymontria dispar) (69). 

Zhu Y, Yang L, Jia Z-J (1999) Novel Highly Oxygenated Bisabolane Sesquiterpenes from Cremanthodium discoideum. J Nat Prod 62 1479... 

Huang, J.M., Nakade, K., Kondo, M., Yang, C.S. and Fukuyama, Y. (2002) Brine shrimp lethality test active constituents and new highly oxygenated seco-prezizaane-type sesquiterpenes from lllicium merrillianum. Chemical and Pharmaceutical Bulletin (Tokyo) 50(1), 1 33-1 36. 

Other highly oxygenated bicyclic marasmane sesquiterpenes have been isolated from an EtOH extract of L. vellereus, which for many aspects seems an inexhaustible mine of Lactarius sesquiterpenes of any kind (see Table 24). The very unstable 5,10a,13-trihydroxymarasm-7(8)-ene (6.7) is accompanied by the 13-normarasmane isomers 6.12 and 6.13 (32) The latter ketones can derive from lactaropallidine (6.6) by (J-elimination and oxidation at C-7. 

P. roqueforti that produce toxic metabolites which include the tremorgenic indoles and a group of sesquiterpenoids. PR Toxin (5.34) and the eremofortins are the best known of these highly oxygenated eremophilane sesquiterpenes. 

Illicium sesquiterpenes, which occur exclusively in the genus Illicium, can be taxonomically regarded as significant markers, and also most of them make up unique highly oxygenated structures. What is... 

Several hybrid sesquiterpene-dimethyl orsellinate metabolites are known from Aspergillus sp [111-114], All of these are highly oxygenated and have undergone rearrangements. Biosynthetic studies have demonstrated that the precursor of the terpenoid portion is famesyl pyrophosphate and of the nonterpenoid portion is a bis-C-methylated polyketide [115]. 

Many sesquiterpenoid plant-derived kairomones have been reported (Hedin et al, 1974 Kelsey et al., 1984). In addition to monoterpenes, many sesquiterpenes that are not highly oxygenated also are found in essential oils. Several are known to possess kairomonal activity. (-f )-a-Copaene (58), from orange fruits, is an attractant for the Mediterranean fruit fly, Ceratitis capitata (Teranishi et al., 1987). a-Famesene (59), from the skin of several varieties of apple and pear fruits, attracts newly hatched larvae of the codling moth, Laspeyresia pomonella, a serious pest of pome fruits (Jacobson, 1982 Sutherland et al., 1977). 

Merten J, Hennig A, Schwab P, FrohUch R, Tokalov SV, Gut-zeit HO, Metz P. A concise sultone route to highly oxygenated 1,10-seco-eudestnanolides-enantioselective total synthesis of the antileukemic sesquiterpene lactones (—)-eriolanin and (—)-eriolangin. Eur. J. Org. Chem. 2006 12(4) 1144-1161. 

The oils have a high terpene hydrocarbon content (>90%, mainly (+)-limonene), but their content of oxygen-containing compounds differs and affects their quality. Important for aroma are aldehydes, mainly decanal and citral, and aliphatic and terpenoid esters. The sesquiterpene aldehydes a-sinensal [17909-77-2] and/3-sinensal [6066-88-8], which contribute particularly to the special sweet orange aroma, also occur in other citrus oils, although in lower concentration [369-370a, 370d, 394,421, 430-438]. 

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