Tetrahydro-2,2-dimethyl-5- furan

In recent years, a great diversity of structurally well-defined functionalized fullerenes has been designed and synthesized for that purpose. Some of them exhibit pronounced solubility in water (vide infra). But even for compounds being virtually insoluble in water, stable aqueous phases can be obtained in plenty of cases by diluting stock solutions of the compounds in polar organic solvents with various amounts of water. Notably, dimethyl sulfoxide (DMSO) and tetrahydro-furan (THF) have turned out to be excellent surfactants for preparing stable aqueous fullerene solutions (Angelini et al., 2005 Cassell et al., 1999 Da Ros et al., 1996 Gun kin et al., 2006 Illescas et al., 2003). Also cosolvents such as dimethylforma-mide (DMF) and methanol can be used to promote water solubility. After subsequent dilution of a saturated solution of C60 in benzene with THF, acetone and finally water, actually stable aqueous suspensions of pristine fullerene can be obtained (Scrivens et al., 1994). 

Terecamphene 3a,8a,9,9a-Tetrahydro-5,8a-dimethyl-3-inethylene-naphtho- [2,3-b]-furan-2,6(3H,4H)-dione (-)-Camphene Yomogin... 

Indolizines with a saturated six-membered ring may be obtained from pyrrole or furan derivatives.225,226 The reaction of 3,4-dimethylpyrryl-magnesium bromide with y-chlorobutyronitrile followed by dilute acid gave 5,6,7,8-tetrahydro-l,2-dimethyl-5-oxoindolizine. 5,6,7,8-Tetrahy-droindolizine can be obtained by the cyclodehydration of 3-(2-furyl)-propylamine over alumina at 400°C. The same product is obtained by the treatment of 3-(2-pyrryl)propyl cyanide with hydrogen chloride in the presence of boron trifluoride etherate catalyst, followed by Wolff-Kishner reduction of the intermediate ketone. 

There have been two additional experiments which verified this basic picture of the nuclear hyperfine interaction in hemins. Johnson (78) increased the spin-lattice relaxation time by performing the Mossbauer experiment under field and temperature conditions which provide a large value of H/T. At 1.6 °K and in an applied field of 30 kG, a magnetic hyperfine interaction corresponding to that expected for high spin Fe(III) and for the g-values is measured experimentally. Recently, Lang et al. have found that a portion of hemin chloride dissolved in tetrahydro-furan at 1 mM concentration displays a hyperfine interaction at 4 °K in zero applied magnetic field. Their conclusion is that a portion of the hemin is present in a monomeric form in this solvent, a situation which is not apparent to any extent in water, acetic acid, chloroform, or dimethyl sulfoxide (77) at any concentrations used. 

Lithium methanetellurolate, generated from methyl lithium and tellurium in tetrahydro-furan, could not be used because the tellurolate was converted to dimethyl tellurium and dimethyl ditellurium during the absolutely necessary change of solvent from tetrahydro-furan to acetonitrile4. 

DIMETHYL-2-n-PENTYLTETRAHYDROFURAN (Furan, tetrahydro-2,2-dimethyl-6-pentyl-)... 

Z. Sun and R. S. Hosmane, Fulgides and photochromism. Synthesis of (E)-and (Z)-5-dicyano-methylene-4-dicyclopropylmethylene-3-[l -(2,5-dimethyl-3-furyl)ethylidene] tetrahydro-furan-2-one, Tetrahedron Lett., 36, 3453-3456 (1995). 

Bernsteinsaure (1-Hydroxy-1-methyl-ethyl)- (Terebansaure) E19a, 556 (En + 2-Propanol) Butandioate Dimethyl 3-Hydroxy-2-methyl- E21a, 733 (2-H - 2-CH3) Furan 2.5-Dimethoxy-3,4-methylen-dioxy-tetrahydro- E14a/1, 4-[3,4-(OH)2-THF + Br- CH2-C1] Monoperhexandisaure E13/1, 774 (Cl - O-OH)... 

Furan 2-Brommethyl-5,5-dimethyl-tetrahydro- VI/3, 537 2-Heptanon 3-Brom- V/4 195, 196 Hexanal... 

Furan 2-Aminomethyl-5-(2,4-dioxo-1,2,3,4-tetrahydro-pyrimidino)-2,5-dihydro- IV/lc, 578 Imidazo(l,2-a]pyridin 1,5-Dimethyl-8-nitro-7-oxo-l,2,3,7-tetrahydro-E15/3, 2790 [cycl. (R2N)2C = CH-N02 4- Diketen] 1,3-Oxazol 4-Cyan-5-(diethoxy-methylen-amino)- E4, 565 (Het — NH2 + Orthoester) Pyrazin 3-Amino-2-methoxycarbo-nyl-5-propanoyl- E9b/2, 324 (H - CO-R)... 

Cyclohexen 4,5-Dicarboxy-l-methoxy- VII/2b, 1794 Furan 3,5-Dimethyl-2,4-dioxo-3-ethoxycarbonyl-tetrahydro- VI/2, 681... 

Furan 3-(Amino-ethoxy-methyl)-5,5-dimethyl-2-oxo-tetrahydro-E15/2, 1775 [aus R —C(OR) = NH2]... 

Dimethyl-3-(hexahydropyrimi-din-2-yliden)-2-oxo-tetrahydro-E15/2 2103 (2-NH2 -3-COOR —4.5-H2 — furan + 1,3-... 

Furan /7-3-Dimethylamino-2,2,5,5-tetramethyl-tetrahydro-Vl/3, 573 Heptansaure 2,3-Dimethyl- -me-thylamid E5, 1089 (Michael-Add.)... 

Furan 3-Carboxy-3,5-dimethyl-2-oxo-5-phenyl-tetrahydro- E19a, 661 (Carbonsaure + En/Lacton-Bildung)... 

Wannamaker W, et al. (S)-l-((S)-2- (l-(4-amino-3-chloro-phe-nyl)-methanoyl)-amino -3,3-dimethyl-butanoy l)-pyrrolidine-2-carboxylic acid ((2R,3S)-2-ethoxy-5-oxo-tetrahydro-furan-3-yl)-amide (VX—765), an orally available selective interleukin (IL)-converting enzyme/caspase-1 inhibitor, exhibits potent antiinflammatory activities by inhibiting the release of IL-lbeta and IL-18. J. Pharmacol. Exp. Ther. 2007 321 509-516. 

Before going into the methods for radical reactions it most be said tlmt polycondensation or polyaddition have led to more industrial preparation. In this connection epoxy resins, the polyurethanes obtained from prepolymers and, more recently, more specialized polymers such as the PEB AC (ATOCHEM), amid-ether or polyimids (KHERIMIDE from RHONE POULENC must be mentioned). Moreover, it is interesting to note that the ionic methods (cationic or anionic ones) have not produced industrial products (except dihydroxy poly (dimethyl siloxanes), poly (tetrahydro-furanes)) but they have facilitated theoretical studies both on the analytical aspects and the materials we can obtain. 

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