3.4- Dimethyl-3-hexene

The reaction of trimethylstannylsodium with two geminal dihalides, 6,6-dichloro-5,5-dimethyl-1-hexene and 6,6-diiodo-5,5-dimethyl-l-hexene, gave evidence of a single electron transfer pathway. An initial electron transfer from MetSn- to the geminal dihalides leads to the haloradical (X ), which then serves as the precursor to all the reactions and products detailed in Scheme 37195. 

Competing radical, carbanion, and carbene pathways in the reaction of 6-iodo-5,5-dimethyl-1-hexene with LDA in THF. (Adapted from reference 155.)... 

Dimethyl-1-hexanol 2.3-Dimethyl-1-hexene 5,5-Dimethyl-1-hexene 2.3-Dimethyl-2-hexene 2,5-Dimethyl-2-hexene c/3-2.2-Dimethyl-3-hexene... 

Hexamethy 1-1,2,4,5-1,2,4,5-tetroxo-nane. See Acetone Compounds under 2,5-Bis(hydroperoxy)-2,5-dimethyl-hexene in Vol 2, p B144-R... 

Propylen und andere a-Alkene wie Buten-(l).... Eikosen-(l)... sowie verzweigte a-Alkene, wie 3-Methyl-buten-(l). 4-Methyl-penten-(l), 4.4-Dimethyl-hexen-(l) u.a. lassen sich dagegen mit einem isolierten, einfachen, alkylierten Ti(III)-Derivat bisher nicht zu Polymeren mit hohen Molekulargewichten umsetzen. 

Ein weiteres Beispiel fiir den Ubergang zur isomeren Carbonyl-Verbindung stellt 3,3-Dimethyl-2-[2-methyl-propen-(l)-yI]-oxiran dar. Bestrahlung einer 0,08molaren Losung in Aceton mit X = 300 nm fiihrt unter 1,2-Verschiebung einer Methyl-Giuppe zu 5-Oxo-2,4-dimethyl-hexen- 2) (60% d.Th.)6 ... 

Dimethyl-hexen-(4)-didl-(1.3) oder 2-Methyl-4-methylol-hexen-(4)-oI-(3)... 

Thermal decomposition of cis- and frans-3,6-dimethyl-3,4,5,6-tetrahydropyridazines affords propene, cis- and frans-l,2-dimethylcyclobutanes and 1-hexene. The stereochemistry of the products is consistent with the intermediacy of the 1,4-biradical 2,5-hexadienyl. The results indicate that thermal reactions of cyclic azo compounds and cyclobutanes of similar substitution proceed with similar stereospecificity when compared at similar temperatures 79JA2069). 

In laser-impulse experiments with chlorophenyldiazirine the carbene could be observed by UV spectroscopy. On addition of defined amounts of alkene the rate of cyclopropanation was measured directly. The rate constants with various alkenes were (lO moF s ) 1-hexene, 1.3 ( )-2-pentene, 34 2-methyl-2-butene, 77 2,3-dimethyl-2-butene, 130 (80JA7576>. 

Similarly complex is the fluorination of the Ihtes methylpyridines (a-, ()-, and 7-picolmes) with cesium tetrafluorocobaltate. 2-Methylpyridme was fluorinated at 270 °C for 180-200 mm, 3- and 4-methylpyridmes were fluorinated at 330 to 340 °C for 150 min All of them afforded the respective polyjluorinated pyridines and perfiuoro-1,2-, 1,3-dimethyl-, and 1-ethylpyrrolidine In addition, perfluoro-2-aza-2-hexene and bis(tnfluoromethyl)amine were isolated m variable yields [27] All the isolated products of the fluorination of 3-methylpyridme (3-picoline) are shown in equation 9. 

When the reaction of perfluQro-3,4-dimethyl-3-hexene with methanol is performed in the presence of pyridine, a perfluorinated dihydrofuran is formed, probably by a process involving generation of an anionic oxygen atom by nucleophilic cleavage of a supposed intermediate ether [27] (equation 24)... 

Hydrogenation of 2,5-diacetoxy-2,5-dimethyl-3-hexyne 10 over 0% palladium-on-carbon is exceptionally complex. Seven different products are formed together with acetic acid. All are hydrogenolysis products arising from the initially formed 2,5-diacetoxy-2,5-dimethyl-3-hexene 11. One of these, 2,5-dimethyl-2-acetoxy-4-hexene 12 forms in as much as 4S yield. 

Two approaches for the synthesis of allyl(alkyl)- and allyl(aryl)tin halides are thermolysis of halo(alkyl)tin ethers derived from tertiary homoallylic alcohols, and transmetalation of other allylstannanes. For example, dibutyl(-2-propenyl)tin chloride has been prepared by healing dibutyl(di-2-propenyl)stannane with dibutyltin dichloride42, and by thermolysis of mixtures of 2,3-dimethyl-5-hexen-3-ol or 2-methyl-4-penten-2-ol and tetrabutyl-l,3-dichlorodistannox-ane39. Alternatively dibutyltin dichloride and (dibutyl)(dimethoxy)tin were mixed to provide (dibutyl)(methoxy)tin chloride which was heated with 2,2,3-trimethyl-5-hexen-3-ol40. 

Oxo-4-[6-carboxy-hexen-(2)-yl]-3-[3-hydroxy-octen-(l)-yl]- 723 3-Oxo-2,4-dimethyl- 622 3-Oxo-1,5-diphenyl- 669... 

Chlor-bis-[c -hexen-(3)-yl-(3)]-aus 3-Hexin und Chlor-boran 56 Chlor- -Diathylather 7, 54 Dichlor- -THF 7 Dicyclohexyl- 7, 52 Diisopino-campheyl- 7 Herstellung 52 f Disiamyl- 6 -Dimethylamin 9 2,3-Dimethyl-butyl-(2)- 6, 53 Organo- 544 f. 

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