Methane + cyclopropane

In agreement with this simple scheme, Ohgaki and coworkers (Makino et al 2005) used Raman spectroscopy to confirm that a mixture of methane + cyclopropane (one of the largest si formers) exhibits a sl/sll transition depending... 

Flammable gases and vapors include acetylene, hydrogen, butadiene, ethylene oxide, propylene oxide, acrolein, ethyl ether, ethylene, acetone, ammonia, benzene, butane, cyclopropane, ethanol, gasoline, hexane, methanol, methane, natural gas, naphtha, and propane. 

In this model, the intermediacy of a monomeric zinc species is postulated. To support this assumption, an examination of the effect of stoichiometry and solvent in cyclopropanation involving the 2,4-pentanediol auxiliary was preformed [59]. In the initial reaction protocol, a large excess of both diethylzinc and diiodo-methane is employed. Such excessive conditions are justified on account of the instability of the zinc carbenoid under the reaction conditions. To minimize the un-... 

The photochemical isomerization of 1,4-dienes 1, bearing substituents at C-3, leads to vinyl-cyclopropanes 2, and is called the di-n-methane rearrangement This reaction produces possible substrates for the vinylcyclopropane rearrangement. 

Malonic acid, amino-, diethyl ester, HYDROCHLORIDE, 40, 24 Malonic acid, bts(hydroxymethyl)-, DIETHYL ETHER, 40, 27 Malonitrile, condensation with tetra-cyanoethylene, 41, 99 2-Mercaptopyrimidine, 43, 6S hydrochloride of, 43, 68 Mercuric oxide in preparation of bromo-cyclopropane, 43, 9 Mesityl isocyanide, 41,103 5-Methallyl-l,2,3,4,5-pentachlorocyclo-pentadiene, 43, 92 Methane, dimesityl-, 43, 57 Methanesiileinyl chloride, 40, 62 Methanesulfonic acid, solvent for making peroxybenzoic acid from benzoic acid, 43, 93... 

Benzyl-cyclopropan 4-Methoxy-benzyl-cyclopropan 4-Chlor-benzyI-cyclopropan Dicyclopropyl-methan... 

Zirconium carbide has also been deposited from the tetrachloride with methane or cyclopropane as the carbon source,... 

While direct photolysis of (46) gave (48), the sensitized photolysis of (46) with acetophenone gave only the cyclopropane product (>93%). These authors favor a stepwise oxa-di-w-methane reaction mechanism (8.69) inasmuch as a concerted reaction should produce the product without a change in multiplicity. That is, the product would have to be formed in the triplet state and not enough energy is available for the product to be formed in an excited state ... 

The deshielding effects of chlorine and bromine appear to be similar, with the chlorine having a greater deshielding influence in the methane examples above but a smaller influence in the cyclopropane example in Scheme 3.11. 

The complex decomposes violently at 0°C, evolving ethane, cyclopropane and methane. 

Dienes can be converted photochemically to vinyl cyclopropanes. This reaction, also named the Zimmerman rearrangement 322), is common to molecules in which two n moieties are substituents on a methane carbon 323). The skeletal changes follow the mechanistic sequence in (3.14). 

The di-rc-methane rearrangement is also a convenient way of obtaining polycyclic fused ring systems as illustrated in the synthesis of a tricyclo-undecane (3.17) 327). In the irradiation of dihydrotriquinacene the initial bonding scheme is identical as in (3.14) but ultimate cyclopropane formation is hindered by structural reasons (3.18) 328). 

These effects can occur when the active site at which a measurable phenomenon occurs is in close proximity to the substituent. Among the many systems exhibiting direct steric effects are ortho-substituted benzenes, 1, cis-substituted ethylenes, 2, and the ortho- (1,2-, 2,1- and 2,3-) and peri- (1,8-) substituted naphthalenes, 3, 4, 5 and 6, respectively. Other examples are d.v-1,2-disubstiUited cyclopropanes, c/ s-2,3-disubstituted norbornanes and ci.s-2,3-disubstituted [2.2.2]-bicyclooctanes, 7, 8 and 9, respectively. Some systems generally do not show steric effects. Vicinally substituted systems such as disubstituted methanes, 10, and 1,1-disubstituted ethenes, 11, are examples, 2,3-Disubstituted heteroarenes with five-membered rings such as thiophenes and selenophenes... 

See Shoppee, "Christopher Kelk Ingold," 351 and Seddon, "The Development of Electronic Theory," 32. Ingold s note (603620) was added to R. M. Beesley and J. F. Thorpe, "The Formation and Stability of Associated Alicyclic Systems. Pt. I. A System of Nomenclature, and Some Derivatives of Methane-II-Cyclopropane and of Methane-III-Cyclopropane," JCS 117 (1920) 591620 also see C. K. Ingold, R. M. 

The reaction in its basic form is illustrated by the conversion of 274 into 275. This transformation shows the control exercised within the two biradicals A and B on the final outcome of the reaction151. Another typical di-jr-methane process, this time with electron-withdrawing substituents on one of the vinyl moieties, arises on acetophenone-sensitized irradiation of the diene 276. This yields the cyclopropane 277 in 35% yield. The... 

On pyrolysis, in addition to the expected C5 olefins, ethylcyclopropane also yields butadiene and methane (this constitutes an important reaction path, the yield of butadiene being about 20% of the total products). This type of decomposition is probably general for ethyl-substituted cyclopropanes, since 1,1-diethylcyclopropane yields 2-ethylbutadiene and methane as well as C7 olefins (Frey and Marshall, 1965). It is possible that the decomposition to the butadiene is also a simple unimolecular process via a transition state such as shown below. 

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