F Cyclopentane

Galvin JB, Marashi F Cyclopentane, y Toxicol Environ Health A 58 57-74, 1999... 

Cyclopentadienylsodium, 1849 p-Cyclopentadienyltrimethyltitanium, 3033 f Cyclopentane, 1933 Cyclopentanone, 1899 Cyclopentanone oxime, 1926 f Cyclopentene, 1885 f Cyclopentylamine, 1985... 

Hydroxy-propyl)- V/ld. 426f. Isopropyloxy- V/ld, 435 f. Cyclopentan 1-Hydroxy-1-phenyl-VI/la,2, 1161... 

Prostaglandin F, a hormone that causes uterine contraction during childbirth, has the following structure. Are the two hydroxyl groups (-OH) on the cyclopentane ring cis or trans to each other What about the two carbon chains attached to the ring ... 

Zu einer eiskalten Losung von 0,029 g (0,76 mMol) Natriumboranat in 5 ml Wasser und 5 ml Isopropanol werden unter Riihren 0,1 g(0,6 mMol) 2,2-Dichlor-l,3-dioxo-cyclopentan gegeben. Man versetzt nach 20 Min. mit Wasser, extrahiert 3mal mit Diathylather, trockuet den Auszug, engt ein und kristallisiert den Riickstand aus Chloroform Ausbeute 0,075 g (75°/0 d.Th.) F 135,5°. 

Malacria and coworkers [274] used an intermolecular trimerization of alkynes to gain efficient access to the skeleton of the phyllocladane family. Thus, the Co-cata-lyzed reaction of the polyunsaturated precursor 6/4-4 gave 6/4-5 in 42% yield. Here, six new carbon-carbon bonds and four stereogenic centers are formed. The first step is formation of the cyclopentane derivative 6/4-6 by a Co-catalyzed Conia-ene-type reaction [275] which, on addition o f his( Iri me ill y I si ly 1) e thy ne (btmse), led to the benzocyclobutenes 6/4-7 (Scheme 6/4.2). The reaction is terminated by the addition of dppe and heating to reflux in decane to give the desired products 6/4-5 by an electrocyclic ring opening, followed by [4+2] cycloaddition. 

Fig. 12.4. Vapor-to-water transfer data for saturated hydrocarbons as a function of accessible surface area, from [131]. Standard states are 1M ideal gas and solution phases. Linear alkanes (small dots) are labeled by the number of carbons. Cyclic compounds (large dots) are a = cyclooctane, b = cycloheptane, c = cyclopentane, d = cyclohexane, e = methylcyclopentane, f = methylcyclohexane, g = cA-l,2-dimethylcyclohexane. Branched compounds (circles) are h = isobutane, i = neopentane, j = isopentane, k = neohexane, 1 = isohexane, m = 3-methylpentane, n = 2,4-dimethylpentane, o = isooctane, p = 2,2,5-tri-metbylhexane. Adapted with permission from [74], Copyright 1994, American Chemical Society...

Droege, A.T., Tully, F.P. (1987) Hydrogen-atom abstraction from alkanes by OH. 6. Cyclopentane and cyclohexane. J. Phys. Chem. 91, 1222-1225. 

Structural characterization of crystalline phases of poly(methylene-l,3-cyclopentane) samples of different microstructures have also been reported (a) Ruiz de Ballesteros, O. Venditto, V. Auriemma, F. Guerra, G. Resconi, L. Waymouth, R. M. Mogstad, A. L. Macromolecules 1995, 28, 2383. (b) Ruiz de Ballesteros, O. Cavallo, L. Auriemma, F. Guerra, G. Macromolecules 1995, 28, 7355. 

Radical [3 + 2 cycloaddition. Cyclopentanes can be prepared by addition of alkenes across vinylcyclopropanes catalyzed by phenylthio radicals formed from (C6H5S)2 and AIBN. A Lewis acid such as A1(CH3)3 can increase the rate and the stereoselectivity of this radical initiated cycloaddition. Thus the combination of the vinylcyclopropyl ester 1 with f-butyl acrylate (2) provides the four possible cyclo-... 

F. C. Gault, J. J. Rooney, and C. Kemball, Catalytic exchange with deuterium of polymethyl-cyclopentanes on metal films Evidence for tt-bonded intermediates, J. Catal. 1, 225 (1962). 

Naphthenic acids, complex carboxylic acids that are believed to have a cyclopentane ring or cyclohexane ring in the molecule, occur in petroleum. They seem to be of little consequence enviromnentally since thermal decarboxylation can occur during the distillation process. During this process, the temperature of the crude oil in the distillation column can reach as high as 395°C (740°F). Hence decarboxylation is possible (Speight and Francisco, 1990) ... 

Unusual amino acids include a class of unnatural a-amino acids such as phenylalanine, tyrosine, alanine, tryptophan, and glycine analogs, and f)-amino acid analogs containing 1,2,3,4-tetrahydroisoquinoline, tetraline, l,2,3,4-tetrahydro-2-carboline, cyclopentane, cyclohexane, cyclohexene, bicyclo[2.2.1]heptane or heptene skeletons. Different selectors were exploited for the separation of unusual amino acids, most of the production being made by Peter and coworkers teicoplanin [41, 56, 84, 90, 93, 124, 141-144], ristocetin A [33, 94, 145, 146], and TAG [56, 147]. Enantiomeric and diastereomeric separations of cyclic -substituted a-amino acids were reported by other authors on a teicoplanin CSP [88, 89], Ester and amide derivatives of tryptophan and phenylalanine were recently analyzed on a Me-TAG CSP [58],... 

Special attention has been paid to acid-catalyzed ring expansion. Sterba and Haensel (J19) reported that the rate of benzene formation from methyl-cyclopentane increases with increasing fluorine content of the catalyst (up to 1.0% F with 0.3% Pt on alumina). At the same time, increasing platinum content also promoted this reaction (up to 0.075% Pt with 0.77% F on alumina). This indicates the remarkable cooperative action of a dual function catalyst (119, p. 11). 

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