Cyclopentene 3-chloro

The polymer, (CsHB04)x, was prepd (together with some monomer) on passing ozone thru a chloro formic so in of cyclopentene. It Is a cryst compd, insol in org solvents reacts violently with coned sulfuric acid a powerful expl Reft 1) Beil 5, (30) 2) C.D. Harries H. 

Highly alkylated l-chloro-2-(trimethylsilyl)cyclopentenes 44, which are of interest as possible cyclopentyne precursors, were prepared by reacting 3-chloro-3-methyl-l-(trimethylsilyl)but-l-yne (45) with 1,1-dialkylated or 1,1,2-trialkylated ethylenes in the presence of titanium tetrachloride35. Because of the low S/v 1 reactivity of 45, the yields of the products were moderate. The stepwise [3 + 2]-cycloaddition mechanism discussed above was proven by the isolation of the intermediate acyclic adduct (in 74% yield) when 45 and isobutene were reacted in the presence of BCI3. Under these conditions, the intermediate 46 could be trapped by Cl since BCI4 is more nucleophilic than TiC.15 (equation 16). 

The results of the olefin oxidation catalyzed by 19, 57, and 59-62 are summarized in Tables VI-VIII. Table VI shows that linear terminal olefins are selectively oxidized to 2-ketones, whereas cyclic olefins (cyclohexene and norbomene) are selectively oxidized to epoxides. Cyclopentene shows exceptional behavior, it is oxidized exclusively to cyclopentanone without any production of epoxypentane. This exception would be brought about by the more restrained and planar pen-tene ring, compared with other larger cyclic nonplanar olefins in Table VI, but the exact reason is not yet known. Linear inner olefin, 2-octene, is oxidized to both 2- and 3-octanones. 2-Methyl-2-butene is oxidized to 3-methyl-2-butanone, while ethyl vinyl ether is oxidized to acetaldehyde and ethyl alcohol. These products were identified by NMR, but could not be quantitatively determined because of the existence of overlapping small peaks in the GC chart. The last reaction corresponds to oxidative hydrolysis of ethyl vinyl ether. Those olefins having bulky (a-methylstyrene, j8-methylstyrene, and allylbenzene) or electon-withdrawing substituents (1-bromo-l-propene, 1-chloro-l-pro-pene, fumalonitrile, acrylonitrile, and methylacrylate) are not oxidized. 

Carbon tetrachloride. Chloroform, 2-Chlorophenol, Cyclohexanol, Cyclopentene, 1,1-Dichloroethylene, irans-l, 2-Dichloroethylene, IV.yV-Dimethylaniline, lV,lV-Dimethylformamide, 2,4-Dimethylphenol, 2,4-Dinitrotoluene, 1,4-Dioxane, 1,2-Diphenylhydrazine, Ethyl formate. Formaldehyde, Glycine, Methanol, Methylene chloride. Methyl formate, 2-Methvlphenol. Monuron, 4-Nitrophenol, Oxalic acid, Parathion, Pentachlorophenol, Phenol, l idine. Styrene, Trichloroethylene, Vinyl chloride Formylacetic acid, see cis-l,3-Dichloropropylene, irans-1,3-Dichloropropylene IV-Formylcarbamate of 1-naphthol, see Carbaryl Formyl chloride, see Chloroethane, Chloroform, sym-Dichloromethyl ether, ds-1,3-Dichloropropylene, irans-ES-Dichloropropylene, Methyl chloride. Methylene chloride. Trichloroethylene, Vinyl chloride lV-Formyl-4-chloro-o-toluidine, see Chlornhenamidine. 

The only practical laboratory preparation of cyclopentadiene is by the depolymerization of dicyclopentadieneA M 3-Chloro-cyclopentene has been prepared by the addition of hydrogen chloride to cyclopentadiene.2 7 8 9 10... 

Chloro-2-nitrosooctane 4-Chloro-4-nitroso-2,6-dimethylheptane 6-Chloro-6-nitrosoundecane 1 -Chloro-1 -nitrosocyclopentane 1 -Chloro-1 -nitrosocyclohexane 1 -Chloro-1 -nitroso-2-methylcyclohexane 1 -Chloro-2-ni trosocyclopentane dimer 1 -Chloro-4-nitroso-2-cyclopentene dimer l-Chloro-2-nitrosocyclohexane dimer... 

A three-neck, round-bottomed flask containing magnesium metal turnings (7.2 g, 0.299 moles), is equipped with a Friedrich condenser and kept under a nitrogen atmosphere. Tetrahydrofuran (300 ml) is added and the contents are allowed to stir. A solution of l-chloro-5-methoxyheptane (48.1 g, 0.292 moles) is added in small portions and refluxed. The mixture is allowed to stir for 3 hours. The resultant dark yellow solution is cooled to -25°C, and the condenser is removed and replaced with a dry ice addition funnel. A solution of 3-chlorocyclopentene (29.9 g, 0.292 moles) is added over a period of one hour. The viscous solution is poured into two liters of saturated ammonium chloride, extracted with ether, and dried over anhydrous sodium sulfate. Distillation yields 3-(5-methoxyhept-l-yl)cyclopentene (51.5 g, 0.262 moles) as clear, colorless oil boiling at about 90°C/0.3 mm and 54°C/0.1 mm. 

Schenk et al. have used the a-chloro nitroso compound 93 for the reaction with cyclopentene 98 in order to solve the problem with the instability of the allyl amine product formed from the reaction with nitroso compounds [56c]. The product formed, 99, rearranges to the stable nitrone hydrochloride salt 100, which is easily hydrolyzed to the hydroxylamine 101 (Eq. (23)). 

Thus cyclopentene reacts with tribromomethyl phenyl sulfone to give a high yield of addition product (equation 106). Samarium iodide catalysis gives a good yield of addition product upon reaction of l-chloro-2-iodoethanes with 1-alkenes (equation 107)690. The product from this reaction has been used to prepare a cyclic target molecule in several further steps. a-Bromoesters also undergo a similar reaction, the product from which upon treatment with KOH gives lactones directly. 

The reaction of A TV -dimethylethylidenediamine with 1-chloroperfluoro-cyclopentene forms a five-membered heterocycle (6-chloro-7,8,8,9,9-penta-fluoro-1,4-dimethyl-1,4-diazaspiro[4,4]non-6-ene) 91, whereas... 

Figure 2. Synthesis of (1 S,4R)-4-t-butyldimethylsilyloxy-3-chloro-2-cyclopenten-1-ol. Reagents a) PPL (25%) b) PDC/DMF (91%).

Reaction of cyclopentene oxide with mercaptohexanoate 9 in the presence of sodium methoxide in methanol at room temperature produced the trans-hydroxyester 10. This ester was hydrolyzed to the acid 11, which was treated with methanesulfonyl chloride in pyridine and afforded the rrans-chloro acid 12 in 82% yield. The fact, that no c/s-chloro acid was obtained is an evidence for the formation of a symmetrical episulfonium intermediate 13. 

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