Famesyl acetate

Dodecatrien-1-ol, 3,7,11-trimethyl-, (E,E)-] (Note 1) and 40 ml. of dry pyridine (Note 2) is prepared in a stoppered 250-ml. Erlenmeyer flask, and 40 ml. of acetic anhydride is added in four portions over a 15-minute period. The mixture is stirred well and allowed to stand for 6 hours and then poured onto 250 g. of ice. Water is added (400 ml.), and the mixture is extracted with five 100-ml. portions of petroleum ether (b.p. 60-68°). The organic extracts are combined and washed in succession with two 50-mi. portions each of water, 5% aqueous sulfuric acid, and saturated aqueous sodium bicarbonate. Anhydrous magnesium sulfate (ca. 50 g.) is used to dry the petroleum ether solution, which is then concentrated on a rotary evaporator to provide 28-29 g. (94-98%) of famesyl acetate as a colorless oil (Note 3). 

External cooling is now discontinued, and 21.4 g. (0.12 mole) of A-bromosuccinimide [2,5-Pyrrolidinedione, 1-bromo-] (Note 5) is added. Stirring is continued until all of the solid is dissolved (ca. 1 hour). The resulting solution, which may be pale yellow, is concentrated with a rotary evaporator (bath temperature 40—45°) to a volume of about 300 ml. and extracted with five 120-ml. portions of ether. The combined ether extracts are dried over anhydrous magnesium sulfate (20-50 g.), and removal of solvent at reduced pressure provides an oil, which is purified by column chromatography on silica gel (Note 6). Pure bromo-hydrin acetate is obtained as a colorless oil in amounts of up to 26 g., a 65% yield based on famesyl acetate (Notes 7 and 8). 

The isoprenoid polyenes famesyl acetate, geranyl acetate and squalene underwent oxidative poly cyclisation to bis-, tris- and penta-tetrahydrofurans with RuO /aq. Na(IO )/CH3CN-EtOAc [185]-[188]. This oxidative polycyclisation of squalene with RuO was shown to lead to the cis-threo-cis-threo-trans-threo-trans-threo-trans penta-tetrahydrofuranyl diol product, this configuration being determined by 2D-NMR (Fig. 3.14) [185]-[188] cf mech. Fig. 1.8 [185]. 

An intramolecular cycloaddition of the tetradecatrienyl nitroethyl ether 263 was used in the synthesis of the 14-membered bicyclic precursor 265 of crassin acetate 266, a cembrane lactone possessing antibiotic and antineoplastic activity (332). Nitro compound 263 was obtained from famesyl acetate (262) in several steps and was then treated with phenyl isocyanate and triethylamine to give the tricyclic isoxazoline 264 (Scheme 6.98). Conversion to ketone 265 was accomplished by hydrogenation of the cycloadduct with Raney Ni and boric acid followed by acetylation (332). In this case, the isoxazoline derived from a 3-butenyl nitroethyl ether moiety served to produce a 3-methylenetetrahydropyran moiety (332). 

AD of 2,6- , -famesyl acetate (3) with 8 as ligand occurred selectively at the terminal double bond to give 5 with 96% ee (position selectivity of about 120 1). In a special solvent system consisting of /ert-butanol-water-methylcyclohexane, at ca. 50% conversion of squalene (4) diol 6 was obtained in 32% yield with 90% ee. Here, the position selectivity was 8 1 [51. 

Selective epoxidMion. van Tamelen and Curphey noted that NBS in an aqueous polar solvent (1,2-dimeihoxyethane)generated HOBr, and that this reagent showed some selectivity in reaction with double bonds. The method was used for selective epoxida-tion of the terminal double bond of famesyl acetate (I) to give 10,11-epoxyfamesyl acetate (4). Complete details of this transformation have been described by Hanziik. ... 

Famesyl acetate is treated with NBS in r-butanol containing water to give the bromo-hydrin (2) in about 65 % yield. The bromohydrin is converted into the epoxide (3) by treatment with KjCOj in methanol. Acetylation of (3) gives 10,11 -epoxyfamesyl acetate (4) in about 60% overall yield. 

In a similar way, Grieco reported the synthesis of fra/u-squalene from rran.r-famesyl acetate and the corresponding sulfone and Liu prepared difluororetinal analogs. 

With 114 in hand, deprotection of the acetate unit, followed by acid-induced cyclization, furnished epoxy-alcohol 115 in good yields. The authors used another acid-catalyzed cyclization to form the C-ring of the desired fragment 116 in a regio- and stereoselective manner. Thus, functional group manipulation of 115 and cyclization upon exposure to Ti(0-iPr)4 [62] afforded compound 116 in 58% yield. This synthesis proceeded in 14 steps from famesyl acetate (108) with 1.5%... 

Faraneol, 361 Famesol, 295 Famesyl acetate, 50 Favorskii rearrangement, 457 Ferric chloride, 69,110,111,236,250 Ferric chloride-Dimethylformamide, 236-237... 

Photoinduced electron transfer from donors such as prenyl acetate, geranyl acetate, all-/ra/w-famesyl acetate, and all-/ra j-geranylgeranyl acetate to 1,4-dicyano-2,3,5,6-tetramethylbenzene, 1,4-dicyanonaphthalene, and 9,10-dicya-noanthracene in the presence of l,r-biphenyl as co-donor in acetonitrile produces the radical cation of biphenyl and the radical anion of the electron acceptors. Geranyl acetate is observed to photocyclise, and the mechanism of this process which involves reaction of its radical cation with water is discussed. Allyl glycosides (76) can be photodeprotected to give (77) via (78) by irradiating with di-t-butyl peroxide in the presence of bromotrichloro-methane. ... 

The radical cations of diene systems in cyclic molecules are also capable of reaction as demonstrated by Demnth, Roth and their coworkers. They have studied the influence of phase on the photochemical reactivity of some naturally occurring dienes. Thns the irradiation of the diene 10 in homogeneous solution (acetonitrile/water) in the presence of an electron-accepting sensitizer such as cyanonaphthalene (CN) or DCB brings about fraws,cw-isomerization only. However, when the electron transfer reaction is carried out in the presence of sodinm dodecyl sulphate, transannular hydrogen abstraction reactions yield the two prodncts 11 and 12. Similar reactivity is observed with frans-geranyl acetate 13 and all-trawi-famesyl acetate 14. The authors report that these cyclizations are the flrst examples of biomimetic processes brought about under SET conditions. 

Unibiovit. [Induchem AG] Famesol/ famesyl acetate bloids. 

Although most attention has focussed on a cationic mechanism in the oxidative cyclization of squalene [20]. Breslow was concerned with the possibility that nature utilizes a free-radical pathway [21]. and studied the addition of benzoyloxy radical to trans, trani-famesyl acetate [22]. The benzoyloxy radicals generated by CuCl-catalyzed thermal decomposition and copper(II) benzoate was added to provide a termination mechanism. Excluding any intervention of a carbocationic process, Breslow obtained a tran -decalin compound (20 30% yield) bearing an exomethylene moiety. As pointed out by Breslow, despite a limited biochemical interest , this work evidenced a new synthetic reaction of considerable potential . An application shortly followed with the first example of a triple cyclization by Julia [23]. Triene isomers 40 were treated by benzoylperoxide in benzene and alforded after saponification alcohol 41 in 12% yield as a single diastereomer (relative stereochemistry confirmed by an X-ray analysis) with a similar tra 5-decalin system (A and B rings. Scheme 14). 

Isolongifolene ketone exo Ketosesquine 29548-30-9 Famesyl acetate 29586-23-6 Copper abietate 29590-42-9 Isooctyl acrylate SR 440 29598-76-3... 

Isolongifolene ketone exo Ketosesquine 249-689-1 Famesyl acetate 249-707-8 Isooctyl acrylate SR 440 249-793-7 Crodamol OHS Dermol 00 Estalan 718 Estalan OV Kessco DHS Naturechem OHS Norfox 171 Octyl hydroxystearate Schercemol OHS Wickenol 171 249-794-2 Cetyl caprylate 249-818-1 Diisodecyl qlutarate 249-862-1 Bernel Ester EHP Cegesoft C 24 Cegesoft C 25 Ceraphyl 368 Crodamol OP Elfacos EHP Estalan 816 Estalan-OP Estol 1543 Estol EHP-b 3652 Exceparl EH-P HallStar OP Jeechem OP Kessco EHP Lexol EHP Liponate EHP Octyl palmitate... 

Caryophyllene alcohol acetate Cedryl acetate Famesyl acetate Guaiol acetate Nonoxynol-1 Ci7H OsS Na Sodium nonoxynol-1 sulfate C17H28O8S4... 

Further, (E,E) famesyl acetate is selectively synthesized by the coupling reaction of halides as shown in eq. (19.55) [98,99]. 

Ambrette seed oil Hibiscus abelmoschus Seed SD (Z)-7-/jexadecan-16-oUde, ambrettolide, 5-tetradecen- 14-olide, 2E, 6 -famesyl acetate... 

The total synthesis of hongoquercin B has been completed in nine steps from famesyl acetate using a double biomimetic strategy, a Pd(0)-catalyzed regioselective decarboxylative famesyl migration, cycloaromatization to produce the resor-cylate, and a cationic epoxydiene cyclization (Scheme 9.48). The single epoxyfamesyl stereocenter was used to control all the remaining four stereocenters of the tetracyclic core [57]. 

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