Cyclododecatriene results

The homologue c/s,ris,c -l,5,9-cyclododecatriene [111] adopts conformations in which homoconjugation is not possible. Any stabilization that may result from homoaromaticity obviously does not compensate for the increased strain in the crown conformation [112] (required for conjugation) (Untch and Martin, 1965 Anet and Rawdah, 1980). 

Type [55] complexes are obtained from cyclooctadienes (74), too, but also from cy-clododecatrienes (59, 117), hexadienes (765), and butadienes (755). Some of these reactions also lead to tetraruthenium olefm clusters. Of these, the complex [7 ] has been mentioned already, and is obtained from cyclooctadiene (74, 75, 283), whereas the complex [59] results from cyclododecatriene (56, 59). 

Methyl 8-oxooctanoate-4,5-D2, 35, and methyl 12-oxododecarbate-4,5,8,9-D4, 36, have been synthesized32 as shown in equations 13 and 14 by monoozonization and sodium acetate cleavage of 1,5-cyclooctadiene and 1,5,9-cyclododecatriene, respectively. The resultant unsaturated aldehydic acids 37 and 38 have been converted to the corresponding acetal esters, which have been deuteriated with Wilkinson s catalyst33 and hydrolysed to the deuterium-labelled aldehydic esters 35 and 36 in 47% and 49% overall yields and... 

Nickel-triarylphosphite complexes catalyze the dimerisation of butadiene to cyclooctadiene. Cyclododecatriene is an unwanted by-product, which results from trimerization catalyzed by the same catalyst. Table 3.2 shows the product yields using various ligand-metal complexes (the remainder in each case is a tarry polymeric material). 

Reaction of excess butadiene with (Ci2Hig)Ni results in displacement of the triene and trimerization of C4H6 (608). At 20°C a new molecule of cyclododecatriene is produced while at —40°C the product, illustrated by structure (194), is considered to involve a C12 chain with a trans double bond and two terminal w-allyl groupings. 

Both cis, trans, trans- and aii-iraws-l,5,9-cyclododecatriene yield upon reaction with Zeise s dimer in acetone, the compounds bis(olefin)-yellow-orange plates melting at about 130°C (456). Dissolution of the all-trans product in an organic solvent results in loss of olefin to produce the polymeric species (Ci2Hi8)4(PtCl2)6 (456). An attempted preparation of the platinum(II) complex of cis,[Pg.320]

Reaction with carbon monoxide at room temperature effects an electron migration resulting in ring closure. Then cyclododecatriene is displaced by more CO molecules ... 

To extend the generality of these results, we examined the photooxygenation of trans, trans, fmn5-l,5,9-cyclododecatriene (28). The... 

As another catalysis, the authors investigated the reaction of complexes 451, 453, and 454 with butadiene. Although 454 was not catalytically active, 451 and 453 were. To achieve the reaction, the complexes were treated with butadiene in the presence of 10 equiv of diethylaluminum chloride. Whereas 451 resulted in a trans,trans,trans- to trans,trans,cis-cyclododecatriene ratio of 0.5 1, this ratio was 3.9 1... 

Figure 3. Ni(0) catalysts for butadiene cyclodimerization and cyclotrimerization. Filled circles, triangles and squares represent results for 1,5 cyclodiene, vinyl-cyclohexene and cyclododecatriene formation, respectively with a low molecular weight catalyst (-C H40P(0C(SH4)2) Open circles, triangles and squares are for PEoiig-bound Ni(0) catalysts using PEoiig-C H40P(OC H4)2 as a ligand.

Technical 1,2,5,6,9,10-HBCD is produced industrially by addition of bromine to czs-trfl s-fra 5-l,5,9-cyclododecatriene, with the resulting mixture containing three predominant diastereoisomers a-, p- and y-HBCD. Normally, the y-isomer is the most dominant in the commercial mixtures (ranging between 75 and 89%), followed by a- and / -isomer (10-13% and 1-12%, respectively) [21,22]. 

Dramatically differing effects of phase-transfer catalysts on the cyclopropanation of cw,trans,trans-cyclododecatriene (61) and a series of dienes have been reported. Addition of dichlorocarbene to (61) results in tris-cyclopropanation when cetyltri-methylammonium bromide (i) is employed, whereas with benzyl-P-hydroxyethyl-dimethylammonium ion (ii) as catalyst only monocyclopropanation (of the more strained bond) is observed (Scheme 7). From the extensive study it may be concluded that, for dichlorocarbene addition, the P-hydroxyethyl catalyst restricts potential polycyclopropanation to monocyclopropanation at the most highly substituted (or strained) double bond. With dibromocarbene a different situation results. Catalyst (i) does not effect the addition of dibromocarbene to styrene, cyclohexene, or allyl bromide while catalyst (ii), with the P-hydroxyethyl function, effects dibromocyclo-propanation, in yields of up to 80 %. 

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