1-Dodecene, epoxidation

DODECENAL see DXU280 DODECENE EPOXIDE see DXU400 DODECENYLSUCCINIC ANHYDRIDE see DXVOOO DODECOIC ACID see LBLOOO... 

Sulphated zirconia catalysts can be acidic or superacidic depending on the method of treatment. A variety of acid-catalysed reactions, referred to earlier in this section, can be carried out with sulphated zirconia. Yadav and Nair (1999) have given a state-of-the art review on this subject. Examples of benzylation of benzene with benzyl chloride / benzyl alcohol, alkylation of o-xylene with. styrene, alkylation of diphenyl oxide with 1-dodecene, isomerization of epoxides to aldehydes, acylation of benzene / chlorobenzene with p-chloro benzoylchloride, etc. are covered in the review. 

Several efficient procedures for alkene epoxidation using Oxone were reported, such as Oxone/aqueous NaOH, Oxone/acetone, Oxone/water , Oxone/PTC/benzene/ aqueous buffer solution or Oxone/2-butanone system. Thus, sorbic acid can be regioselectively oxidized using Oxone/aqueous NaOH to 4,5-epoxy-2-hexenoic acid in 84% yield. Similarly, cyclooctene is oxidized to cyclooctene oxide in 81% yield, just by stirring it with Oxone in water . 1-Dodecene is epoxidized in good yield by Oxone/PTC in benzene aqueous buffer solution. It is otherwise difficult to epoxidize 1-dodecene by other oxidizing reagents. ... 

Shorthand notation for pheromone molecules for example, (Z)-7-dodecen-l-yl acetate is shortened to Z7-12 OAc where the Z denotes the double bond configuration (Z or E), 7 the double bond position, 12 the number of carbons in the chain, OAc indicates the functional group as an acetate ester. Aid = aldehyde, Co A = coenzyme A, D = deuterium, Epox = epoxide, He = hydrocarbon, me = methyl group, OH = alcohol. 

The new procedure was found to be applicable to octcne-l, dodecene-I, and methyl methacrylate, olefins which previously have been epoxidized only with the potent pertrifluoroacelic acid. 

In addition, Ox-Ti-P samples were found to be efficient catalysts in the epoxidation of bulky organic substrates such as norbornylene (Table 2). For comparison, the reaction was also carried out in the absence of any catalyst. As seen, the catalytic activity of Ox-Ti-p samples was comparable to that of Ti-P. We also obtained very high conversions in the epoxidation of 1-dodecene over Ox-Ti-P. 

Poly(ethylene glycol)-supported manganese porphyrins were tested in the epoxidation of cyclooctene, 1-dodecene, cyclohexene, styrene, and indene with PhIO or H2O2 in the presence of N-alkylimidazoles as axial ligands [51]. The polymers were soluble in the reaction mixtures and could be precipitated and reused. Epoxide yields from 80 to 100%, except for 1-dodecene (38% yield), were obtained using PhIO as oxidant. 

A series of polymer-anchored epoxidation catalysts was obtained by modifying Merrifield resin with imidazole [61], diphosphines [62], or piperazine [63] followed by treatment with UV-activated Mo(CO)6. High activities in the epoxidation of cyclic (cyclooctene, cyclohexene, indene, and a-pinene) as well as linear alkenes (styrene, a-methylstyrene, 1-heptene, 1-dodecene, cis- and frans-stilbene) were observed using TBHP as oxidant. The catalysts were recovered and reused up to 10 times in the epoxidation of cyclooctene without loss of activity. 

Comparing the epoxidation results of terminal olefins having different carbon atoms, it can be seen that the conversion based on H2O2 went up from 81.9% to 90.6% with decrease in carbon atoms from 1-dodecene to 1-octene (entries 2 and 3) and the reaction time required dropped from 5 to 4 h. 

The first materials produced by this method which have obtained commercial importance are monoepoxides such as octylene oxide, dodecene oxide, and a mixture of 1,2-epoxy hexadecane and 1,2-epoxy octadecane. These epoxides are used as stabilizers for vinyl polymers and as diluents for epoxy resins. 

Dinuclear Mn(IV) catalysts were successfully applied for the epoxidation of 4-benzoic acid and styrene in aqueous systems [18], for the epoxidation of styrene and dodecene in two-phase systems [19g] as weU as in methanol and acetone [17d, 19b,g,h], and for the epoxidation of olefins in acetonitrile [19i], aqueous acetonitrile [17f, 19c], acetone [17d, 19b,h], methanol [19i], and acetone-methanol-water mixtures [19j]. Enantioselective epoxidations of olefins have been reported for chiral triazacyclononane derivatives boimd to Mn(OAc2) 4 (H2O) in methanol [19k], Heterogenization of the Mn catalysts on silica for the epoxidation of styrene and cyclohexene, on zeolites for olefin epoxidation, and on a solid MnS04 H2O also for olefin epoxidation [20] has also been described. A polymeric structure bearing a dense arrangement of 1,4,7-triazacyclononane moieties can be synthesized by... 

An in situ method for epoxidations with dimethyldioxirane using buffered aqueous acetone solutions of Oxone has been widely applied.The epoxidation of 1-dodecene is particularly impressive in view of the difficulty generally encountered in the epoxidation of relatively unreactive terminal alkenes (eq 7). A biphasic procedure using benzene as a cosolvent and a phase-transfer... 

Lai er Rings.—Humulene A -monoepoxide (250) is the major product of WClg-n-butyl-lithium reduction of humulene triepoxide. It is reduced by lithium aluminium hydride or lithium-ethylamine to the 5-alcohol (251 X = OH, Y = H). The isomeric 4-alcohol (251 X = H, Y = OH) can be prepared from humulene-bis-epoxide. All -cis-cyclododeca-l,5,9-triene reacts with chlorosulphonyl isocyanate to give a good yield of mono-adduct, which can be hydrolysed to the p-lactam (252). Reactions of iV-bromosuccinimide in the presence of water, methanol, and acetic acid, with CIS- and trans-cyclododecene have been examined. cis- and trans-l-Nitrocyclo-dodecenes are interconverted on irradiation further irradiation causes isomerization to 3-nitro-trans-cyclododecene. ... 

---