3,3-Dimethyl-5- -4-penten

Dibrom-3-oxo-2,4-dimethyl-pentan wird kathodisch (an Quecksilber in aproti-schen Solventien) zu 3-Oxo-2,4-dimethyl-penten-(l) reduziert3. Das intermediar gebil-dete Cyclopropanon-Derivat kann mit Nukleophilen (z. B. Alkoholen, Essigsaure) abge-fangen werden (s. S. 669)3,4. 

As to the B/branched a-olefin copolymers, the degree of cocrystallization falls progressively with the size of the comonomer units. Apart from the B/3MB system, already discussed, in the B/4-methyl-pentene-l copolymers partial isomorphous replacement of monomer units in the two homopolymer crystal phases is observed, with lattice dimensions changes (Table 1). With 4,4 -dimethyl-pentene-l both homopolymer phases occur, physically separated, without lattice dimension changes. In each case, for high butene contents, the PB II phase is observed, i.e. the phase with larger CSA, which indicates that at least some degree of cocrystallization is always present. 

Proton shifts occur occasionally in cationic polymerizations. 4,4-Dimethyl-pentene-1 polymerizes quite normally via the carbon-carbon double bond at low temperatures, whereas additional monomeric units with three carbon main chain atoms per monomeric unit are produced at higher temperatures ... 

The most important products from PP are compounds with 3 carbons (oligomers) [212], yet the major products are different as a function of the experimental conditions. Thus, besides 2,4-dimethyl-pentene, identified as major products were ethane, propane, 2-methylpentene [207c], 2-pentene, propene, 2,4,6-trimethylnonene-l [212, 279], and propene, tetra-methylhendecene, and trimethylnonene [209]. Stereoisomerism also influences the PP decomposition mechanism [280a]. 

The same reaction that gave 2 4 4 trimethyl 2 pentene also yielded an isomeric alkene This second alkene produced formaldehyde and 4 4 dimethyl 2 pentanone on ozonolysis Identify this alkene... 

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