Vinyl cyclopentanes

The a-nucleated polypropylene is used for power cable insulatioa A polymeric a-nucle-ating agent comprises monomer units derived from a vinyl compound. The vinyl compound is selected from the group consisting of vinyl cyclohexane, vinyl cyclopentane, vinyl 2-methyl cyclohexane and vinyl noibomene, 3-methyl-l-pentene, styrene, p-methyl-styrene, 4-methyl-1-pentene, 3 -methyl-l-butene, and 3-ethyl-l-hexene. Nucleating agent is present in the polymer composition in the amount of 0.0001 to 0.2 wt%. ... 

Hydrosilylation of I-vinyl-1-cyclohexene (77) proceeds stereoselectively to give the (Z)-l-ethylidene-2-silylcyclohexane 78, which is converted into (Z)-2-ethylidenecyclohe.xanol (79)[74]. Hydrosilylation of cyclopentadiene affords the 3-silylated 1-cyclopentene 80. which is an allylic silane and used for further transformations[75.75a]. Cyclization of the 1,3,8, lO-undecatetraene system in the di(2.4-pentadienyl)malonate 69 via hydrosilylation gives the cyclopentane derivative 81. which corresponds to 2.6-octadienylsilanc[l8,76]. 

A Ni(0)-catalyzed l,oo-hydrosilylation across the two dienyl moieties of 1,3,8,10-undecatetraene 9 proceeds regioselectively and stereoselectively and provides vie-trans-divinyl cyclopentane products 10 in modest yield (Eq. 3) [13]. The reaction shows an interesting stereoselectivity with respect to the substituent geometry both of the vinyl groups of 10a and 10b are stereoisomeric to each other, and one of the two double bonds is cis and the other is trans. 

The utility of this metallo-ene-type reaction has also been demonstrated by the reaction of 1,6- or 1,7-enynes bearing a chiral 1,2-diphenylethylene acetal moiety as the leaving group. The reaction was found to proceed with excellent chiral induction to give optically active cyclopentane and cydohexane derivatives, respectively, which was followed by reaction of the resulting vinyl titaniums with electrophiles, as exemplified in Eq. 9.60, s.p. 348 [108]. 

In chlorophyll iron as complex-forming metal is replaced by magnesium (Willstatter). The structure of chlorophyll differs from that of haemin as follows. In chlorophyll one propionic acid chain (a) in oxidised form has condensed with a methine carbon atom to form a cyclopentane ring which takes the position at (c) of the vinyl ethyl. Further the two carbonyl groups are esterified and one of the four pyrrole rings is partially hydrogenated... 

VINYL PROPIONATE 2-HYDROXYETHYL ACRYLATE LEVULINIC ACID METHYL ACETOACETATE GLUTARIC ACID VALERONITRILE n-BUTYL ISOCYANATE N-HETHYL-2-PYRROLIDONE L-GLUTAMIC ACID CYCLOPENTANE 2-METHYL-1-BUTENE... 

Cyclohexanol, Cyclopentane, Cyclopentene, 1,2-Dichloroethane, Diethyl phthalate, 1,4-Dioxane, Ethephon. Ethylamine, Ethylene dibromide, Ethylenimine, p-Propiolactone, Tetraethyl pyrophosphate, TCDD, 1,1,1-Trichloroethane, Trichloroethylene, Vinyl chloride Ethylene chlorohydrin, see Bis(2-chloroethyl) ether Ethylenediamine, see Ethylene thiourea. Maneb Ethylene glycol, see Bis(2-chloroethyl) ether, 1,2-Dichloroethane, Ethylene chlorohydrin. Ethylene dibromide... 

Reaction of linear conjugated dienes with la at —10 °C in hydrocarbon solvent in the presence of McsSiCl/AlCls affords stereospecific tra i-l-silyl-3-vinyl-cyclopentanes, indicating a [3 + 2] cycloaddition of the allyl group of la with a carbon arbon double bond of the diene [Eq. (9)]. In the [3 + 2] annulation reaction, of greater significance is the tram conformation of the trimethylsilyl group and vinyl groups. 

Shibuya H, Fujioka H, Yamamoto Y, Suzuki K, Kitagawa I, Chemical ttansfotmation of tetpenoids, IV, Acid tteatment of (3./ )-1-vinyl-, (3f )- 1-hydtoxyptopenyl and (3./ )-1 -epoxyethyl-5-methoxy-1,2,2-trimethyl-cyclopentane derivatives Ring enlargement relations and successive migrations of methyl residues, Chem Pharm Bull 30 1280—1288, 1982. 

Cyclopentanes, synthesis, 66, 10 CYCLOPEKTANONE SYNTHESIS, 66, 87, 92, 93 Cyclopentanone, 2-carbomethoxy-3-vinyl, 66, 56 Cyclopentanone, 2-ethenyl-2-methyl (88729-76-4), 66, 94 2-CYCLOPENTEN-l-ONE, 3-METHYL-2-PENTYL-, 65, 26 Cyclopropane, l-trimethy1s1lyloxy-1-ethoxy-, 56, 44 Cyclopropanecarboxylic acid chloride, 66, 176... 

Tsuji has reported the cyclization/distannylation of bis( 1,3-dienes) that form bis(functionalized) 1,2-dialkenyl-cycloalkanes, although the scope of the transformation was quite limited.In one example, reaction of ( , )-6,6-bis(ethoxycarbonyl)-l,3,8,10-undecatetraene and hexamethyldistannane (1.2equiv.) catalyzed by Pd(DBA)2 in toluene at room temperature for 20h gave /ra/ i--( ,Z)-l,2-bis-[2-(trimethylstannyl)vinyl]cyclopentane trans- E,Z)-108] in 90% yield as a single regioisomer and diastereomer (Equation (69)). 

The (co)polymerization of dienes can be a good method for the preparation of polymers with reactive vinyl groups, a method that enables the preparation of polymers possessing plural vinyl groups per polymer chain. A fluorinated bis(phenoxy-imine) Ti complex was shown by Coates and co-workers to convert 1,5-hexadiene to poly(methylene-l,3-cyclopentane-fti-3-vinyl tetramethylene), which contained multiple vinyl groups. As already discussed, Saito et al. and others revealed that bis(phenoxy-imine) Ti complexes favored secondary insertion. " This is probably responsible for the formation of 3-vinyl tetramethylene units. Likewise, the same catalyst system can form sPP-/ -poly(methylene-l,3-cyclopentane-z -3-vinyl tetramethylene) from propylene and 1,5-hexadiene. Very recently. 

Several groups have prepared cyclopentane systems by intramolecular Michael addition.72 Reaction of the triester (292 Scheme 37) with phenyl vinyl ketone (293) and base produces the cyclopentane (295) in good yield via an intermolecular (giving 294) and subsequent intramolecular Michael addition.72 When the Michael acceptor is a cyclohexenone (Scheme 38), the c/s-fused hydrindanone is produced (298 or 297).72b 72f Spiro systems can also be formed by these reactions (300a,b equation 66) in which the Michael addition gives a spiro ring fusion. 

The carbonyls Fe(CO)5 and [CpFe(CO)2]+ (2) form stable cationic complexes with alkenes, which are used for both protection and activation of alkenes [1]. [CpFe(CO)2]+ (2 abbreviated as Fp+) is prepared by the reaction of cyclopentadienyl anion (1) with Fe(CO)5, followed by oxidative cleavage with bromine, and used for the protection of alkenes. The electron density of the double bond is decreased by the coordination of [CpFe(CO)2]+ and hence this bond is activated to nucleophilic attacks. Introduction of nucleophiles, such as the carbon nucleophile of malonate, to cyclopentene becomes possible via the formation of the complex 3, and the stable tftmv-er-alkyliron complex 4 of cyclopentane is prepared. The vinyl ether complex 6 is obtained easily from the a-bromoacetal 5, and reacts with an enolate of ketone 7 as an... 

The initial retrosynthetic analysis for a route to travoprost, using the Newton-Roberts route, provided three key synthons a) the a-chain was derived from the commercially available Wittig salt, (4-carboxybutyl)triphenylphosphonium bromide b) the co-chain required a route to the single enantiomer mixed cuprate reagent, most conveniently derived from the propargylic alcohol via the trans-vinyl iodide, to be developed and c) the cyclopentane core could be derived from the single enantiomer protected bromohydrin (Figure 30.3).llc 25... 

Although methyl 2-siloxycyclopropanecarboxylates are cleaved by certain electrophiles, only tetracyanoethylene (TCNE) as a carbon electrophile could directly be added to phenyl or vinyl activated cyclopropanes providing cyclopentane derivatives 61). 

The styrene monomer first may be polymerized to about 65% conversion in the absence of water, and then the blowing agent (cyclopentane) may be added with additional peroxide. This solution is suspended in water in the presence of potato starch, and the polymerization is finished (74). By another modification a styrene solution of waste polystyrene and peroxide is suspended by poly (vinyl alcohol) in water, and pentane is added to the suspension after the solids content of the oil phase is greater than 70% (133). Polystyrene particles may also be suspended in water by a mixture of poly (vinyl alcohol) and a phenyl sulfonate and then a mixture of equal parts of pentane and catalyzed styrene (8% each on polymer) is diffused into the polymer. The temperature is elevated, and the polymerization is completed (23). 

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