Cyclododecenes

Cyclododecene (cis and tians) was similady tiansformed to the cyclic enone, which is an impoitant intermediate in the preparation of perfumary products, such as muscone [541 -91 -3J. 

Other methods have been described to produce dodecanedioic acid. Cyclododecene is prepared from cyclododecatriene by partial hydrogenation. Ozonolysis of the cyclododecene followed by oxidation of the intermediate ozonides gives dodecanedioic acid (72). Hydrogenation of riciaoleic acid gives 12-hydroxystearic acid, which upon treatment with caustic at high temperatures, 325—330°C, gives a mixture of undecanedioic and dodecanedioic acids. 

Another process for the production of dodecanedioic acid is by oxidation of cyclododecene using a two-phase system in which mthenium tetroxide serves as the oxidizing agent in the organic phase, and is regenerated in the second phase, an aqueous phase containing cerium(IV) ions (75). 

To a 3QQ-mL, round-bottomed flask fitted with a water separator, (Note 1) which contains 15 g of Linde 4A molecular sieve l/16-1nch pellets and Is filled with toluene, are added 7.3 g (0.04 mol) of cyclododecanone, 11.4 g (0.16 mol) of pyrrolidine, 100 mL of toluene, and 0.57 g (0.004 mol) of boron trifluoride etherate. The solution is heated under reflux for 20 hr. The water separator is replaced by a distillation head, and about 90 mL of the toluene is removed by distillation at atmospheric pressure. The residue containing l-(N-pyrrolidino)-l-cyclododecene (1) is used in the next step without further purification (Note 2). 

Pure l-(N-pyrrolidino)-l-cyclododecene, bp 144 C (1.5 inn), may be isolated by distillation through a Vlgreux column. 

E-Cyclooctene is also significantly straine4 but less so than -cycloheptene. As the ring size is increased, the amount of strain decreases. The. E-isomers of both cyclononene and cyclodecene are less stable than the corresponding Z-isomers, but for cycloundecene and cyclododecene, the E-isomers are the more stable. Table 3.10 gives data concerning the relative stability of the C7 through C12 cycloalkenes. 

Trichloro-l,2,4-triazine reacts with cycloheptene and cyclododecene to give 2,6-dichloropyridine derivatives (e.g., 10) via an intermediate dihydropyridine formed by Diels-Alder addition and loss of Nj <96JCS(P1)519>. 

Mikroreaktoren sind so klein wie ein Fingerhut, Handdsblatt, May 1998 Steep progress in microelectronics, sensor and analytical techniques in the past transport intensification for catalysis first catalytic micro reactors available partial oxidation to acrolein partial hydrogenation to cyclododecene anodically oxidized catalyst supports as alternatives to non-porous supports study group on micro reactors at Dechema safety, selectivity, high pressure exclusion of using particle solutions limited experience with lifetime of micro reactors [236],... 

A m-RuCl2(CO)2(PPh3)2 complex, which catalyzes hydrogenation of dienes and monoenes, becomes useful in the presence of added phosphine for selective hydrogenation of 1,5,9-cyclododecatriene to cyclododecene the catalyst is a HRuCl(CO)2(PPh3)2 hydride that operates via steps analogous to those of reactions (9)-(11) (144, 145). 

The very unusual selective hydrogenation of ,/3-unsaturated aldehydes to the unsaturated alcohols, Eq. (30), has been accomplished using [RhCl(CO)2]2 in the presence of tertiary amines under oxo conditions (162). RhCl(PPh3)3 systems under similar conditions reduce the olefinic bond (162), as do Co2(CO)8 systems in the presence of amines or phosphites (163). Further details on the versatile Rh(BH4)(amide)py2Cl2 systems (/, p. 280) have appeared (164, 165) ketones are also slowly hydrogenated (166), and 1,5,9-cyclododecatriene has been selectively reduced to cyclododecene (167). 

Use of molten salts as solvent allows easy separation of organic products by distillation (376), and in this way PtCl2 with tetraalkylammonium salts of SnCl3 and GeCl3 has been used to selectively hydrogenate 1,5,9-cyclododecatriene to cyclododecene the salts in this case act as both solvent and ligand (377). A molten salt medium has been used in a homogeneously catalyzed Fischer-Tropsch synthesis (see Section VI,B). 

As expected, although TS-1 is more active and selective in the epoxidation of linear alkenes (such as hex-l-ene and dodec-l-ene), the large-pore Ti-beta is more active in the case of the bulkier cyclohexene (TON of 14 v.v. 1 for TS-1) and cyclododecene (TON of 20 vs. 5 Table VII) (11). 

A new class of heterogeneous catalyst has emerged from the incorporation of mono- and bimetallic nanocolloids in the mesopores of MCM-41 or via the entrapment of pro-prepared colloidal metal in sol-gel materials [170-172], Noble metal nanoparticles containing Mex-MCM-41 were synthesized using surfactant stabilized palladium, iridium, and rhodium nanoparticles in the synthesis gel. The materials were characterized by a number of physical methods, showed that the nanoparticles were present inside the pores of MCM-41. They were found to be active catalysts in the hydrogenation of cyclic olefins such as cyclohexene, cyclooctene, cyclododecene, and... 

---