Ethylene derivatives Double bonds

Section 2 20 Carbon is sp hybridized in ethylene and the double bond has a ct com ponent and a rr component The sp hybridization state is derived by mix mg the 2s and two of the three 2p orbitals Three equivalent sp orbitals result and their axes are coplanar Overlap of an sp orbital of one car bon with an sp orbital of another produces a ct bond between them Each carbon still has one unhybridized p orbital available for bonding and side by side overlap of the p orbitals of adjacent carbons gives a rr bond between them... 

Since double bonds are no longer present, these compounds are more stable than the corresponding furan derivatives. Tetrahydrofurfuryl alcohol—ethylene oxide adducts [31692-85-0] are also usehil solvents for paint stripping formulations (136,141,143). 2-Methylfuran is a good solvent, but... 

The double bond migration which normally occurs on forming ethylene ketals from A -3-ketones has frequently been utilized to form derivatives of the A -system. The related transformation of A -3-ketones into A -3-alcohols is usually accomplished by treatment of the enol acetate (171) (X = OAc) with borohydride. This sequence apparently depends on reduction of the intermediate (172) taking place faster than conjugation ... 

In another approach to analogs, nortestosterone is first converted to the thioketal by treatment with ethylene dithiol in IUe presence of boron trifluoride. (The mild conditions of this reaction compared to those usually employed in preparing the oxygen ketals probably accounts for the double bond remaining at 4,5.) Treatment of this derivative with sodium in liquid ammonia... 

Ethylene oxide, the simplest epoxide, is an intermediate in the manufacture of both ethylene glycol, used for automobile antifreeze, and polyester polymers. More than 4 million tons of ethylene oxide is produced each year in the United States by air oxidation of ethylene over a silver oxide catalyst at 300 °C. This process is not useful for other epoxides, however, and is of little value in the laboratory. Note that the name ethylene oxide is not a systematic one because the -ene ending implies the presence of a double bond in the molecule. The name is frequently used, however, because ethylene oxide is derived pom ethylene by addition of an oxygen atom. Other simple epoxides are named similarly. The systematic name for ethylene oxide is 1,2-epoxyethane. 

A series of nitrated and unsaturated hydrocarbons. The base molecule for nomenclature purposes is usually called the "ethylene series1 because the first member is ethylene, C2H4 hence a molecular type CnH(2n-x)Nx02x s derived. Other compds in the series are named after corresponding paraffins by adding to the stem ene or ylene such as 1-nitro propylene, C3H5NO2. Olefms with two conjugeted double bonds are called dienes , such as butadiene. 

A cyclobutene ROCM sequence was also used in a synthesis of racemic sporochnol (410), a naturally occurring feeding deterrent toward herbivorous fish (Scheme 80) [170]. Exposing cyclobutene 406 (0.01 M in boiling 1,2-dichloroethane) in the presence of ethylene to second-generation catalyst C (8 mol%) led to 1,5-diene 407 in 73% yield, along with 9% of the homodimer derived from 407 by involving the less hindered double bond. Site-selective hy-... 

Alder-Ene Reactions. An ene-iminium one-pot cyclization proceeds smoothly in a mixture of water-THF (Eq. 12.66). 138 The reactivity of the ene-iminium substrates is highly dependent on the substitution pattern of the ethylenic double bond. This methodology can be used to form homochiral pipecolic acid derivatives. 

The alkene series of hydrocarbons is characterized by having one double bond in the carbon chain. The characteristic formula for members of the series is C H2 . Since there must be at least two carbon atoms present to have a carbon-to-carbon double bond, the first member of this series is ethene, C2H4, also known as ethylene. Propene (propylene), C,Hh, and butene (butylene), C4HK, are the next two members of the series. Note that the systematic names of these compounds denote the number of carbon atoms in the chain with the name derived from that of the alkane having the same number of carbon atoms (Table 21-2). Note also that the characteristic ending -ene is part of the name of each of these compounds. 

Nenajdenko et al. described the first example of addition of a 1,2-dication to C-C mutiple bonds. The only S-S dication found to participate in this reaction was the highly strained dication 115 derived from 1,4-dithiane. The reaction with alkenes 119 proceeded under mild conditions and led to derivatives of dithioniabicyclo[2.2.2]octane 120 as shown in Equation (33) and Table 21 <1998JOC2168>. This reaction was sensitive to steric factors and proceeded only with mono and 1,2-disubstituted ethylenes. Only alkenes conjugated with aromatic or cyclopropane moieties underwent this reaction. For the 1,2-disubstituted alkenes used in this study, the relative configuration of substitutents at the double bond was preserved and only one diastereomer was formed (see entries 2 and 3). 

Later, Patterson and Hibbert (S3) stated that ultraviolet absorption of lignin corresponded with the absorptions of hydroxy derivatives of 4-(4,hydroxy-3,methoxyphenyl)-l-propanone and l-(4,hydroxy-3, 5,dimethoxyphenyl)-4-propanone. These authors, therefore, assumed the presence in lignin of a carbonyl group, or of an ethylenic double bond conjugated with an aromatic nucleus. They ascribed the 280 mp band to m-position freedom in the benzene ring and the 310 mp baud to a masked carbonyl group in conjugation with a benzene nucleus. 

Alternating copolymers of ethylene with olefins containing double bonds in the cis configuration, like ds-2-butene, cyclopentene, cycloheptene,115 and norbomene,116 have been described. Recently also copolymers of carbon monoxide with styrene and styrene derivatives, having syndiotactic117 and isotactic118 configurations, have been synthesized and characterized. 

The chlorodifluoromethylated ketone 130 proved to be a valuable substrate for promoting SrnI subtitution reaction with sodium phenylthiolate and to generate a new a-(phenylthio)-a,a-difluoroacetophenone derivative 131 (Equation 57) <2001TL3459>. Upon treatment with nitronate anions under classical SrnI reaction conditions or MW irradiation, 6-chloromethyl-5-nitro-imidazo[2,l- ]thiazole 132 yielded 5-nitroimidazothiazoles bearing a trisubstituted ethylenic double bond at the 6-position (Equation 58) <2001SC1257>. 

The chemical structure for common chlorinated solvents is shown in Figure 4.5. Chlorinated solvents such as TCE and PCE are composed of double-bonded carbon or ethylene structures with three and four chlorine atoms, respectively. The ethane derivative 1,1,1-TCA has three chlorine atoms. Freon is a chlorofluorocarbon and is also an ethane derivative with four chlorine atoms and three fluoride atoms. 

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