Cyclo hexene

One of the advantages of the enamine alkylation reaction over direct alkylation of the ketone under the influenee of strong base is that the major product is the monoalkylated derivative 29,32). When dialkylation is observed, it occurs at the least substituted carbon in contrast to alkylation with base, where the a-disubstituted product is formed. Dialkylation becomes the predominant reaction when a strong organic base is added and an excess of alkyl halide is used (29). Thus 1-N-pyrrolidino-l-cyclo-hexene (28) on treatment with two moles of allyl bromide in the presence of ethyl dicyclohexylamine (a strong organic base which is not alkylated under the reaction conditions) gave a 95 % yield of 2,6-diallylcyclohexanone (29). 

These researches on the synthesis of the terpenes were commenced in 1900, and has been carried on with considerable success and conspicuous ability ever since. It was considered necessary to synthesise terpineol, and BO establish the formula which analytic reactions supported. The first necessary step was to synthetically prepare the l-methyl-A -cyclo-hexene-4-earboxylic acid, of the formula—... 

Knochel et al. described Pd-catalyzed Negishi cross-coupling reactions between zinc organometallics and aryl iodides in [BMMlM][Bp4]. Scheme 5.2-20 illustrates the reaction for the formation of a 3-substituted cyclohexenone from 3-iodo-2-cyclo-hexen-l-one [82]. 

The synthesis of the trisubstituted cyclohexane sector 160 commences with the preparation of optically active (/ )-2-cyclohexen-l-ol (199) (see Scheme 49). To accomplish this objective, the decision was made to utilize the powerful catalytic asymmetric reduction process developed by Corey and his colleagues at Harvard.83 Treatment of 2-bromocyclohexenone (196) with BH3 SMe2 in the presence of 5 mol % of oxazaborolidine 197 provides enantiomeri-cally enriched allylic alcohol 198 (99% yield, 96% ee). Reductive cleavage of the C-Br bond in 198 with lithium metal in terf-butyl alcohol and THF then provides optically active (/ )-2-cyclo-hexen-l-ol (199). When the latter substance is treated with wCPBA, a hydroxyl-directed Henbest epoxidation84 takes place to give an epoxy alcohol which can subsequently be protected in the form of a benzyl ether (see 175) under standard conditions. 

A similar study has been reported using l-nitro-2-[(S,S)-2-phenylpropylsulfinyl]-l-cyclo-hexene and zinc enolates of tetrahydro-2(3//)-pyridinones34. 

Analog erhalt man aus 1-Phenyl-propen J-Phenyl-propan6 bzw. aus 4-Methyl-cyclo-hexen 4-Methyl-cyclohexan6. 

Trichloroacetamido-l-hexene, 58,9,11 Trichloroacetonitrile, 58,5, 7, 10,11 2,3,5-Trichloro-3,6-di-/a-f-butyl-5-cyclo-hexene-l,4-dione, 55, 33 2- 2,2,2-T richloroethoxy)carbonyl-... 

The intramolecular formal [3+3] cycloaddition reaction of l- [l-phenyl-2-(4-oxobut-2-enyloxy)ethyl]amino cyclo-hexen-3-one at 150°C in the presence of piperidinium acetate afforded /ra 3--l,4a-77-l-phenyl-l,2,4,4a,7,8,9,10-octahydro[l,4]oxazino[4,3- ]quinolin-7-one <2002JA10435>. At 85°C, the 6-(l-piperidnyl)-l,2,4,4a,5,6,7,8,9,10-dec-ahydro derivative formed, which could be converted into the l,2,4,4a,7,8,9,10-octahydro derivative by heating at 150 °C. Cyclization of iV-[(2-butyl-2-oxoethoxy)acetyl]-3,4-dimethoxyphenylethylamine on the action of TFA gave llb-butyl-1,3,4,6,7,1 lb-hexahydro[l,4]oxazino[3,4- ]isoquinolin-4-one <1997JOC2080>. 

In the tetrabromide of 4-vinyl-l-cyclo-hexene, the higher alkylated double bond could be selectively deprotected by cpe [177]. 

No. of pulse < C Hexane Hexenes Hexa- dienes Cyclo- hexane Cyclo- hexene 1,3-Cyclo- hexadiene 1,3,5-Hexatriene Benzene... 

Cyclic olefins and diolefins form aerosol even when present at very low concentrations, as confirmed by smog-chamber studies for cyclo-hexene and 1,6-heptadiene. ... 

Biological. The pure culture Aspergillus niger biodegraded isophorone to 3,5,5-trimethyl-2-cyclo-hexene-l,4-dione, 3,5,5-trimethylcyclohexane-l,4-dione, (5)-4-hydroxy-3,5,5-trimethyl-2-cyclohex-l-one, and 3-hydroxymethyl-5,5-dimethyl-2-cyclohexen-l-one (Mikami et al, 1981). 

Ethyl-5-phenyl-2,4,6(l//,3//,5//)-pyrimidinetrione synonym 5-ethyl-5-phenylbarbituric acid. 5-Ethyl-1-methyl-5-phenylbarbituric acid. 5-Ethyl-5-phenyldihydro-2-thioxo-4,6(lEf,5H)-pyrimidine-dione synonym 5-ethyl-5-phenyl-2-thiobarbituric acid. 5-Ethyl-5-hexyl-2-thiobarbituric acid. 5-Ethyl-5-isopentylbarbituric acid. 5-Ethyl-5-(l-methylbutyl)-2-thiobarbituric acid. 5-(l-Cyclo-hexen-l-yl)-l,5-dimethylbarbituric acid. 5-Ethyl-5-(l-methylbutyl)barbituric acid. 5-(l-Cyclohexen-l-yl)-5-ethylbarbituric acid. 

Pro- pylene Isobutyl- ene Cyclo- hexene Ethylene Pro- pylene Isobutyl- ene... 

Hydroxy-5-nitro-bicyclo[3.3.0]oct-2-ene bzw. 9-Hydroxy-l-nitro-bicyclo [4.3.0]non-7-ene sind durch Umsetzung von 1-Nitro-cyclopenten brw. 1-Nitro-cyclo-hexen mit 2-Morpholino-3-oxo-l-buten zuganglich. 

Fig. 3.1. (cont.) (S)(+)-isopiperitenone (3-methyl-6-(5 )-isopropenyl-2-cyclo-hexen-l-one) 17, isopiperitenol (3-methyl-6-isopropenyl-2-cyclohexen-l-ol) 18, isorobinal (4-isopropenyl-3-oxo-l-cyclohexene-1-carbaldehyde) 19, robi-nal (3-oxo-4-isopropylidene-l-cyclohexene-1-carbaldehyde) 20, a, a -acariolide (3-(4/-methyl-3/-pentenyl)-2(5//)-furanone) 21, a,/ -acariolide (4-(4 -methyl-3 -pentenyl)-2(57/)-furanone) 22, / -acariolide (( )-2-(4/-methyl-3/-pentenylidene)-... 

Illustrative of the behavior of afioyclio epoxides toward attack by hydrogen sulfide are reactions of cyclopenten oxide. and cyclo-hexene oxide.391 U B Passage of hydrogen sulfide through alkaline solutions of these substances (Eq. 641) causes first the formation of... 

Epoxide formation is nearly suppressed when massively subeti-tuted olefine, such as 2,2,4-trimethyl-3-hexene among others, ate subjected to the chromic oxide-acetic anhydride reagent,42 Cyclo-hexene yields primarily 2-cyclohexenone and cyclohexane- 1,2-dione777 although some cyclohexane oxide appears to bo formed also (Eq, 111). 

A detailed study " of this method of synthesis has been made during which cyclohexene sulfide was prepared. The fact that cyclo-hexene sulfide is formed from both the 8- and 0-monoacetates of... 

Liquid (herrnul conductivity data urc available for cyclo-hexene from 20°C to 1HCC o... 

A IT9 c7h4ftno 3-(methylam1no)-heptaf uoro-2-cyclo-hexen-l-one L6V BUTJ-/F T CM1 EtOH 60 PY KOAc - 7.5 9.5 DME/SCE 2-0 C=1... 

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