Cis-CYCLOOCTENE OXIDE

This epoxide has been found to be particularly useful in the laboratory in the large-scale preparation of frarty-cyclooctene using the procedure of Whitham.14 trans-Cyclooctane- 1,2-diol is obtained from cis-cyclooctene oxide on treatment with sodium acetate in acetic acid and alkaline hydrolysis of the intermediate trans-2-acetoxycyclooctanol. The trans diol is converted to its benzal-dehyde acetal, which on treatment with butyllithium affords trans-cyclooctene in a stereospecific manner. 

Isomerization of cis-cyclooctene oxide (2, 247 4, 309). In the original work on the isomerization of cis-cyclooctene oxide (1) with lithium diethylamide, Cope reported that (2) and (3) are formed in a 4 1 ratio. In recent work ... 

The desymmetrization works also well with higher substituted meio-epoxides such as ewdo-norbornene oxide (130) , cis-5,6- and 4,7-difunctionalized cyclooctene oxides 132 and 134, giving the alcohols 131, 133 and 135, respectively but for the diastereomer 136, the rearrangement to form the allylic alcohol 138 beside 137 cannot be completely suppressed (equation 29 best results are given). ... 

Denmark et al. employed the chiral phosphoramide 74 (Scheme 13.37) as nucleophilic activator [75]. As summarized in Scheme 13.37, the best enantiomeric excess was observed for cis-stilbene oxide (87%). The study revealed that enantioselectivity was highly dependent on the ring size (cyclohexene oxide cyclopentene oxide > cyclooctene oxide). 

Epoxidation takes place preferentially or more rapidly at electron-rich (i.e., tetraalkylated) double bonds [217]. The reaction is stereospeciflc cis alkenes give cis epoxides, and trans alkenes give trans oxides [211. 1,2-Dimethylcyclopentene is oxidized with peroxybenzoic acid to 1,2-di-inethylcyclopentene oxide in 85% yield [296], and dj-cyclooctene is transformed by hydrogen peroxide into c -cyclooctene oxide in 60-61% yield [1099]. 

Ionization potential of Continued) butenone, 123 cyclic diacetylenes, 305 cyclohexene, 48, 102 cis-cyclooctene, 102 Zraus -cyclooctene, 102 DABCO, 81 dimethyl ether, 123 ethylene, 80, 319 formaldehyde, 123, 319 hydrogen atom, 55, 75 methanol, 123 methyl acetate, 123 methyl acrylate, 123 nitrous oxide (N2O), 172 norbornadiene, 48 norbornene, 48 oxetane, 123 tetrahydrofuran, 123 trimethylamine, 81 water, 123... 

Re(0)2(Tp )] generated in situ from [Re(0)3(Tp )] and PPI13, reacts stereospecifically with epoxides and episulfides. When cis- and trans-cyclooctene oxides are used, a ring-expanded Re(V) diolate is formed. However, when an episulfide such as ethylene sulfide (Fig. 2.47) or cis- or trans-cyclooctene sulfide is employed, a dithiolate species is obtained.209... 

The detailed kinetic studies on the oxidation of saturated hydrocarbons cyclohexane [4,5] and adamantane [26] and epoxidation of unsaturated hydrocarbons [4,5,25] cis-cyclooctene, cyclohexene, styrene and trans-stilbene were done by measuring the rate of reaction with respect to the concentration of each reactant, substrate, catalyst, ascorbic acid, hydrogen ion and molecular oxygen. The dependence of the reaction rate at various initial concentrations of the reactants were determined. While varying the concentration of a particular reactant, the concentrations of other reactants were kept constant under identical physical conditions. 

The stability constants decrease in the order Ki>K2>K3 and K >K4>Ks for oxidation of saturated [5] and unsaturated [5,28] hydrocarbons respectively and their thermodynamic parameters [5,28] are found to be nicely in line with their stability. The order of the reactivity [5,26,28] of the substrates was found to be cis-cyclooctene > cyclohexene > styrene > trans-stilbene > ldamantane > cyclohexane. The reactivity trend was supported by activation parameters which were higher for saturated hydrocarbons [5] than that of unsaturated hydrocarbons [5,28]. 

Cis cyclooctene (3).2 To ice cooled N,N-dimethylcyclooctylamin 1 (5 0 g, 32 mmol) in MeOH (10 ml), was added over 30 min 35% hydrogen peroxide (10 0 g. 99 mmol). Stirring was continued until the amine had been consumed (24 h). The excess of peroxide was destroyed by stirring with platinum black (0 25 g) for 5 h. The platinum was removed by filtration and the filtrate was concentrated in vacuo to a syrup (max. temp 30-40°C), to give 2. Amine oxide 2 was heated under vacuum (10 mm) in a N2 atmosphere and the temperature was raised 1 -27min. Decomposition and distillation began at 100°C and ended at 130°C. 

The effect of different substitution on this transannular rearrangement was further studied on a range of disubstituted cyclooctene oxides. cis-4,7-Di(t-butyldimethylsilyloxy)-cyclooctene oxide 80 yielded a mixture of bicyclic alcohol 81, and alkene 82 arising from reductive alkylation [Eq. (28)] [61,62]. 

Rearrangement of cyclooctene oxides was discovered to be an efficient route to cyclopentanoid terpenes. For example, the conversion of cts -cyclohexene oxide to 2-endo-hydroxy-cis-bicyclo[3.3.0] octane with an amide base was first noted by Cope, Lee, and Petree and was later revisited by Whitesell and White using LDA, with a marked improvement in yield and product selectivity. The protocol was further optimized with... 

Bonchio, M., Carraro, M., Farinazzo, A., et al. (2007). Aerobic Oxidation of cis-Cyclooctene by Iron-Substituted Polyoxotungstates Evidence for a Metal Initiated Auto-Oxidation Mechanism, J. Mol. Catal. A Chem., 262, pp. 36-40. 

The lithium diethylamide-promoted isomerization of cis- and traws-cyclooctene oxide affords different products or the same products in different proportions. This lack of convergence rules out carbene 227 as a common intermediate (Scheme 1-173). Moreover, the c/s-oxirane reacts with isopropyllithium in the presence of (-)-sparteine enantioselectively. ... 

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