1-Heptene hydrogenation

Table I. Effect of Added Ligand on the Rate of 1-Heptene Hydrogenations over Reduced 3...

There are two products that can be formed by syn addition of hydrogen to 2 3 dimethylbi cyclo[2 2 1] 2 heptene Write or make molecular models of their structures... 

Hydrazoic acid reaction with cyclobu-tanecarboxyhc acid, 47, 28 Hydrogenation of t butylazidoacetate to glycme ( butyl ester, 46,47 Hydrogen bromide 46, 43 reaction with y butyrolactone, 46, 43 Hydrogen fluoride anhydrous, precautions in use of, 46, 3 in preparation of mtromum tetra-fluoroborate 47, 57 reaction with benzoyl chloride, 46,4 with boron tnfluonde in conversion of p cymene to m cymene, 47, 40 in bromofluorination of 1 heptene, 46, 11... 

Homoconjugation results in enhanced reactivity of substrates toward ionic hydrogenation. Bicyclo[2.2.1]hepta-2,5-diene forms a mixture of the trifluoroac-etate esters of bicyclo[2.2.1]hepten-2-ol, tricyclo[2.2.1.02 6]heptan-3-ol, and bicyclo[2.2.1]heptan-2-ol in a 62 20 17 ratio on treatment with 10 equivalents of triethylsilane and 20 equivalents of trifluoroacetic acid for 24 hours at room temperature (Eq. 96), 230... 

Bicyclo[2.2.1]hepten-7-one has been prepared by the oxidation of (z-7-hydroxybicyclo[2.2. ljheptene with chromic acid in acetone 2 and with aluminum t-butoxide in benzene with benzoqui-none as the hydrogen acceptor.3 The procedure described here is essentially that of Gassman and Pape.4... 

The hydrogenation of Claisen rearrangement products (R)-(E)- and (S)-(Z)-3,7-dimethyl-4-octenal [obtained highly selectively from (7 )-( )-6-methyl-4-vinyloxy-2-heptene, see p421] to give (S)- and (7 )-3,7-dimethyloctanal, respectively. Authentic samples of these aldehydes were obtained from (5)- and (7 )-citronellal 14°. 

Addition of acetylene to acetone results in the formation of 2-methyl-3-butyn-2-ol, which is hydrogenated to 2-methyl-3-buten-2-ol in the presence of a palladium catalyst. This product is converted into its acetoacetate derivative with diketene [38] or with ethyl acetoacetate [39]. The acetoacetate undergoes rearrangement when heated (Carroll reaction) to give 6-methyl-5-hepten-2-one ... 

Methyl-5-hepten-2-one is converted into linalool in excellent yield by base-catalyzed ethynylation with acetylene to dehydrolinalool [45]. This is followed by selective hydrogenation of the triple bond to a double bond in the presence of a palladium carbon catalyst. 

Industrial synthesis of nerolidol starts with linalool, which is converted into ger-anylacetone by using diketene, ethyl acetoacetate, or isopropenyl methyl ether, analogous to the synthesis of 6-methyl-5-hepten-2-one from 2-methyl-3-buten-2-ol. Addition of acetylene and partial hydrogenation of the resultant dehydroner-olidol produces a mixture of cis- and trans-nerolidol racemates. 

Dehydrolinalool, obtained by ethynylation of 6-methyl-5-hepten-2-one, can be converted into dehydrolinalyl acetate with acetic anhydride in the presence of an acidic esterification catalyst. Partial hydrogenation of the triple bond to linalyl acetate can be carried out with, for example, palladium catalysts deactivated with lead [73]. 

The demands for new alcohols were to a considerable extent satisfied by the commercialization of the oxo synthesis in the United States (1). The synthesis involves reaction of an olefin with carbon monoxide and hydrogen to produce an aldehyde, which is reduced subsequently to a primary alcohol. From branched chain feeds such as pentene, heptene, nonene, and tetrapropylene-hexyl, isooctyl, isodecyl, and tridecyl alcohols have been made available to the plasticizer industry in large volume. These alcohols are mixtures of branched chain isomers owing to the branched nature of the olefin feed. (Oxo hexyl alcohol contains about H 1-hexanol). 

In some preliminary work, 3 was hydrogenated in the presence of a number of ligands, and the resulting solutions were used for the hydrogenation of 1-heptene. Rate data for these reactions are given in Table I. 

The hydrogenation of 2 occurred reasonably well in benzene-ethanol to give a rather poor catalyst for the hydrogenation of 1-heptene. The reduction of 2 in the presence of 6 gave a catalyst which was almost twice as reactive for this hydrogenation (Table II). In both cases though, double bond isomerization occurred almost as rapidly as did hydrogenation of 7 over these reduced 2 catalysts. But in this case, the catalyst prepared from 2 in the absence of 6 was almost completely unreactive, presumably because of the increased bulk of the olefin (Table III). 

The rates of hydrogenation of 1-heptene over a number of catalysts prepared from 2 and a variety of amines and amides are listed in Table IV. The activity of these catalysts is clearly related to the degree of substitution on the nitrogen atom of the amine or amide used in their preparation. This is most obvious by comparing Run 5 with Run 6 and Run 9 with Run 10. 

The hydroformylation of several olefins in the presence of Co2(CO)8 under high carbon monoxide pressure is reported. (S)-5-Methylheptanal (75%) and (S)-3-ethylhexanal (4.8%) were products from (- -)(S)-4-methyl-2-hexene with optical yields of 94 and 72%, respectively. The main products from ( -)(8)-2,2,5-trimethyl-3-heptene were (S)-3-ethyl-6,6-di-methylheptanal (56.6%) and (R)-4,7,7-trimethyloctanal (41.2%) obtained with optical yields of 74 and 62%, respectively. (R)(S)-3-Ethyl-6,6-dimethylheptanal (3.5% ) and (R)(S)-4,7,7-trimethyloctanal (93.5%) were formed from (R)(S)-3,6,6-trimethyl-l-heptene. (+/S)-l-Phenyl-3-methyl-1-pentene, under oxo conditions, was almost completely hydrogenated to (- -)(S)-l-phenyl-3-methylpentane with 100% optical yield. 3-(Methyl-d3)-l-butene-4-d3 gave 4-(methyl-d3)pentarwl-5-d3 (92%), 2-methyl-3-(methyl-d3)-butanal-4-d3 (3.7%), 3-(methyl-d3)pentanal-2-d2,3-d1 (4.3%) with practically 100% retention of deuterium. The reaction mechanism is discussed on the basis of these results. 

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