Cyclopentane Ethanol

A general preparation of 2-acetonyl-2,4,6-triaryl-2//-thiopyrans 58 was discovered in the reaction of corresponding 2,4,6-triarylthiopyrylium perchlorates with ethanolic acetone catalyzed with various dialkylammonium salts (86GEP235455, 86JPR573). This preparative procedure was successfully extended to cyclohexane- and cyclopentane- 1,2-diones as the carbonyl components (89JPR853 90GEP280324). The action of bases on thiopyrylium salts may caused their dimerization to thiopyranyl derivatives under suitable conditions (89KGS479). 

FIGURE 3 2 Solvent extraction efficiencies (EF) as functions of dielectric constants (D), solubility parameters (6), and polarity parameters (P and E -). Solvents studied silicon tetrachloride, carbon disulfide, n pentane. Freon 113, cyclopentane, n-hexane, carbon tetradiloride, diethylether, cyclohexane, isooctane, benzene (reference, EF 100), toluene, trichloroethylene, diethylamine, chloroform, triethylamine, methylene, chloride, tetra-hydrofuran, l,4 dioxane, pyridine, 2 propanol, acetone, ethanol, methanol, dimethyl sulfoxide, and water. Reprinted with permission from Grosjean. ... 

Analogous reactions of 3-diazobicyclo[2.2.1]heptan-2-one with perchloric acid in alcohols, such as ethanol, gave the corresponding ethers, e rfo-3-ethoxybicyclo[2.2.1]heptan-2-one (34%),, n -2-ethoxybicyclo[3.1,1]hcptan-6-onc (41%) and methyl cyclohex-3-enecarboxylate.69 Further examples of the formation of cyclobutanes from cyclopentanes via Wagner-Meerwein-type rearrangements are given in Table 2. 

Cyclopentene is produced in excellent yield by the selective hydrogenation of cyclopentadiene. Both Raney nickel in cold ethanol solution74 and Cu/A1203 aerogel in the gas phase75 are selective catalysts. The cyclopentene is converted to cyclopentane at a rate much lower than that of diene transformation to cyclopentene. Other catalytic processes for the hydrogenation of cyclopentadiene yield cyclopentane as the principal product. 

CAMPHOS = l,2,2-trimethyl-l,3-bis(diphenylphosphinomethyl)cyclopentane. All reactions were carried out in a medium-pressure Parr apparatus for 24 hr at 300 psi hydrogen at 60°C in 200 ml 1 1 (v/v) deoxygenated ethanol-benzene with a substrate-to-triethylamine mole ratio of 6.25. 

The lithiated sulfone 413 has been alkylated with alkyl bromides623 in the presence of HMPA and with 1,4-dihaloalkanes623,624, acting as an acyl dianion. For instance, treatment of intermediate 413 with the dimesylate 414625 has been applied to the synthesis of the cyclopentane derivative 415, a precursor in the synthesis of 3-oxocarbacyclins (Scheme 107)625. Compound 415 was hydrolyzed to the corresponding cyclopentenone with 50% sulfuric acid in ethanol. 

Iodine and thiourea can be used to form an aminothiazole fused to a cyclopentane ring <2002BML1563>. In this way, 6-aryl-8//-indeno[ 1,2-r/]thiazol-2-ylamine hydroiodide 253 was prepared by treatment of ketone 254 with iodine and thiourea in either DMF or ethanol with heating (Scheme 102) <2005JME5131>. 

The calculations were conducted for aqueous solutions of alcohols (methanol, ethanol, propanols, butanols, and tert-pentanol) and hydrocarbons (normal saturated aliphatic hydrocarbon from propane through dodecane, isobutane, cyclopentane, cyclohexane, cycloheptane, benzene, toluene). 

The close relationship between monoterpenes and insects is, of course, well known, and work has intensified on what attracts, say, bark beetles to appropriate trees. One of the most intriguing aspects is the potentiating effect ethanol has on the aggregation of certain species when in conjunction with the pheromone. This aspect has little to do with total synthesis, but the discovery of new pheromones and defense secretions certainly has. Many are described in this chapter, but one of the more unusual types is the new cyclopentane structure found by Eisner and Meinwald in pheromones of certain carrion beetles, the synthesis of which is described in the appropriate section (Section 6). °... 

A limited number of experiments were conducted to evaluate the last two possibilities. First, the take-up solvent for two test solutes, anthracene and naphthalene, was cyclopentane (with solution concentrations still about 1 mg/mL and injection aliquots still about 0.3 - 0.5 pL into a 20vL loop) instead of 2-methoxy-ethanol. The distortion persisted even when a gentle stream of air was used after aliquot deposition in the sampling loop to blow off the take-up solvent. Furthermore, the onset of the distortion for naphthalene occurred at a lower carbon dioxide density than for anthracene. When the column was changed to a partially chemically deactivated column, Hypersll SAS, where short alkyl chains are bonded to active sites, onsets of peak distortion for anthracene and for naphthalene were shifted to lower carbon dioxide densities (and still different from each other) than for the fully active Hypersll SIL adsorption column. Only slight peak distortion was observed for a Hypersll ODS column at even lower column midpoint densities (0.33 g/mL with the back pressure at 1170 psig, the FLOW setting at 1.90 mL/min, and 40 C distortion was observed for only anthracene and not naphthalene). 

The conditions for the experiments described in this paper were the following Sample Aliquot—0.5 uL of mixtures of approximately 1 mg/mL concentrations Sample Take-Up Solvent—2-methoxy-ethanol, cyclopentane Temperature—60 °C Back Pressure—346 bar (5000 pslg) unless specifically noted Column—5 pm Hypersil SIL, 10 cm long, 4.6 mm ID, Hewlett-Packard 79916 SI Opt.554 for all presented chromatograms, (5 pm Hypersil SAS, 10 cm x 4.6 mm ID material from Shandon Southern Products Limited, Cheshire, UK packed in-house, and 5 pm Hypersil ODS, 10 cm X 4.6 mm ID, HP 79916 OD Opt. 554 for special discussions) Flow Setting—4 mL/ min Linear Velocity—0.5 cm/s Detector Wavelengths—254 nm ex-... 

Further methylation, followed by the action of sodium ethoxide in ethanol, leads to substituted cyclopentanes. 

DimethyIhexane Cyclopentane Cyclohexane Methanol Ethanol 2-Propanol 2-Methyl-2-propanol Dioxane... 

It may be prepared by the condensation of 1-phenyl-cyclopentane carbonyl chloride with 2-(diethylaminoethoxy) ethanol to yield carbetapentane base by the elimination of a mole of hydrogen chloride. The base is dissolved in ethanol and treated with a equimolar portion of citric acid to give the official compound. 

Methylethyl) cyclohexadiene-1 -ethyl formate. See4-(1-Methylethyl) cyclohexadiene-1-ethanol formate (1-Methylethyl) cyclohexane. See Isopropylcyclohexane (1-Methylethyl) cyclopentane. See Isopropylcyclopentane Methyl ethyl diketone. See Pentane-2,3-dione Methylethyl disulfide. See Diisopropyl disulfide 1-Methylethyl docosanoate. See Isopropyl behenate... 

Ethyl cyclopentan-2 oneglyoxylate added dropwise with stirring and cooling below 5 to a soln. of KOH in ethanol-water, more water added, cooled, and cautiously acidified with HCl cyclopentan-2-oneglyoxylic acid. Y 81-92%. R. Mayer, H. Burger, and B. Matauschek, J. pr. 14, 261 (1961). 

The cyclopentane dione (0.154 g 5.58 x 10" mol) in dry ether (5 ml) is added to a vigorously stirred solution of sodium (0.3 g 1.3 x 10 mol) in dry ethanol (10 ml). After cooling to 0°C a solution of 3-methyl-2-butenyl bromide (0.075 g 5.03 x 10 mol) in ether (5 ml) is added. The mixture is stirred for 18 h, diluted with water, acidified (HCI) and extracted with ether. The ethereal layer is separated, washed with water, dried and concentrated in vacuo to an oil. Distillation yields 2-(3-methylbutanoyl)-5-(3-methyl-2-butenyl)-3,4-dihydroxy-4-(4-methyl-3-penten-1-ynyl)-2-cyclopentenone (0.084 g 44%) as a light-yellow oil with a boiling point of 100°C (bath temperature) at 5 X 10" mm Hg. 

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