Frans-Anethole

Itoh and colleagues reported more recently that frans-anethole 86b underwent an analogous [2+2] cycloaddition to cyclobutanes 87 in 21-78% yield with complete frans-selectivity when 5-10 mol% Fe(C104)3 was used as the catalyst [144]. Some ligands were tested and it was found that chiral BOX-type ligands, induced only... 

Methyl chavicol, frans-anethol, methyleugenol, eugenol, chavicol, vanillin... 

In summary, Foeniculum is stated to have three species, F. vulgare (fennel), F. azoricum Mill. (Florence fennel) and F. dulce (sweet fennel). Fennel is widely cultivated, both in its native habitat and elsewhere, for its edible, strongly flavoured leaves and seeds. The flavour is similar to, but milder than, that of anise and star anise. Anethole and fenchone are the major constituents of the solvent extract of seed phenols, free fatty acids, carbohydrates, proteins, vitamins and minerals have been reported in varying proportions. In the mature fruit, up to 95% of the essential oil is located in the fruit, greater amounts being found in the fully ripe fruit. Approximately 45 constituents have been determined from fennel seed oil, the main constituents being frans-anethole, fenchone, estragol (methyl chavicol), limonene, camphene, a-pinene and other monoterpenes, fenchyl alcohol and... 

The GC-MS pattern of fruit volatile oil of star anise (7. vemm Hook) shows the presence of 25 components, which account for 99.9% of the total amount (Padmashree et al., 2007). The major components are trans-anethole (93.9%), estragole (1.05%) and limonene (1.05%) (Table 17.3). Fifteen components are identified from its acetone extract, accounting for 80.27% of the total amount. frans-Anethole (51.81%) is found as a major component, along with linoleic acid (11.6%), l-(4-methoxyphenyl)-prop-2-one (6.71%), foeniculin (5.29%) and palmitic acid (1.47%). 

The main component of anise oil is frans-anethole, which is present at a concentration of 87-94% and which determines the melting point of the oil [263-266b],... 

The phenylpropanoids frans-anethole (61) and fraws-cinnamaldehyde (62) are used as flavoring agents in foods in the United States and some other countries [20]. rrans-Cinnamaldehyde (62) was isolated from Cinnamomum osmophloeum Kanehira (Lauraceae) as a sweet principle, while frans-anethole (61) was isolated as the volatile oil constituent responsible for the sweet taste of several plant species, as listed in Table 1 [92]. These two compounds occur widely in the plant kingdom. Therefore, it is necessary to rule out their presence in any candidate sweet plant by a dereplication procedure in a natural product sweetener discovery program using gas chromatography-mass spectrometry (GC/MS) [46,47],... 

Tetraphenyiporphine-sensitized photooxygenation of frans-anethole (1 b) in CCi4 afforded a 1,2-dioxene (2 b) and an a-diketo epoxide (4b) along with a dihydropyranoi (3 b), 2-hydroxy-4-methoxybenzaldehyde (5 b), 4-methoxyhenz-aidehyde (6 b), 4- ethoxyphenyi vinyi ketone (7b) and frans-anethoie Different product distributions were obtained for 3-methyistyrene and isosafroi. 

The discussion to this point has focused on the addition of bromine to double bonds bearing alkyl substituents. There are significant differences in the addition of bromine to alkenes with aryl substituents. For example, the addition of bromine to aryl-substituted alkenes is not stereospecific. Reaction of ds-j8-methylstyrene (13) with bromine in CCI4 led to the formation of 17% of erythro- (14) and 83% of f/ireo-(l,2-dibromopropyl)benzene (15, equation 9.12). Reaction of frans-jS-methylstyrene under the same conditions yielded 88% of the erythro and 12% of the threo product, When the benzene ring in the trans reactant was substituted with a 4-methoxy group (frans-anethole), the reaction became even less stereoselective, giving 63% erythro and 37% threo product. ... 

Tasmanian type fran -anethole 45%-78%, fenchone 10%-25%, a-pinene 2%-ll%. 

Anethole, anisaldehyde, and myristicin (in aniseed), along with z/-carvone (present in P. anisum plant), have shown mild insecticidal properties. In houseflies, the major (56% by weight) active insecticide in the oil from anise tops was shown to be frans-anethole. Anisaldehyde and anethole increased the toxicity to houseflies when applied at the same as various common insecticides. Anethole also inhibits growth of mycotoxin-producing Aspergillus species in culture. ... 

Asymmetric reduction of unsymmetrically substimted 1,2-diketones with the chiral Ru catalyst gives a partly reduced chiral a-hydroxy ketone at 10°C, while at higher temperature, 40°C, chiral ann-1,2-diols with an excellent ee is obtainable (Fig. 5) [34]. This method can be applied to access (l/ ,2S)-l-(4 -methoxyphenyl)-1,2-propanediol (98% ee), which is a major metabolite of fran -anethole in the rat. 

Irradiation of an ammonia-saturated MeCN-H O solution containing frans-anethole (6a) and m-DCB gave 2-amino-l-(4-methoxyphenyl)propane (26a) as the sole product (Scheme 6.25) [48], The yield of 26a was remarkably improved by the addition of 1,3.5-triphenylbenzene (TPB) or m-terphenyl (m-TP) (Table 6.6). After the photoreaction, these polyphenylbenzenes were recovered in high yields without the reaction with NH3. 

---