Ethylidene iodide

Problem 8.38 Show reagents and reactions needed to prepare the following compounds from the indicated starting compounds, (a) Acetylene to ethylidene iodide (1.1-diiodoethane). b) Propyne to isopropyl bromide,... 

Methylidenation of allylic thioethers. Methylidenation of an allylic phenyl-thioether with methylene iodide-diethylzinc is accompanied by a 2,3-sigmatropic rearrangement to a homologous allylic phenylthioether. The rearrangement is also initiated by ethylidene iodide. Cyclopropanation is not observed. The Simmons-Smith reaction with allylic sulfides results only in formation of an insoluble polymer. 

Problem 8.33 Show reagents and reactions needed to prepare the following compounds from the indicated starting compounds, (a) Acetylene to ethylidene iodide (1,1-diiodoethane). (b) Propyne to isopropyl bromide, (c) 2-Butyne to racemic 2,3-dibromobutane. (d) 2-Bromobutane to trans-2-butene. (e) n-Propyl bromide to 2-hexyne. (/) 1 -Pentene to 2-pentyne. ... 

Ring expansion of aromatic compounds by carbene, carbethoxycarbene, chlorocarbene, and carbenoid is well known 256, 336, 351-356). Muller and co-workers reported the reaction of aromatic compounds with carbene generated from a catalytic decomposition of diazomethane with copper salts, and proposed a bimolecular two-step mechanism involving an inverse ylid for the reaction. Miller (336) proposed another bimolecular two-step mechanism for the reaction of benzene with alkylcarbenoids of aluminum. Baldwin and Smith (25) proposed a concerted mechanism for the reaction of aromatic compounds with carbethoxycarbene. Reaction of alkylbenzene with diethylzinc and ethylidene iodide gives 7-methylcyclohepta-l,3,5-triene derivatives in yield 369). The... 

Piperidininm 1 -[2-(Dimethyl-hydrazono)-ethyliden]- -iodid E14a/3, 231 (R-CHO -... 

Ethylidene Bromide. CH3—CHBr2, Ethylidene Iodide, CHg—CHI2. 

The application of carbenoid reactions, however, gives satisfactory results in certain cases. Thus, ethylidene iodide with diethylzinc transfers an ethylidene group to olefinic double bonds in good yields ". The reaction proceeds in a stereospecific manner (equation 50). Stereochemical control of the addition by hydroxyl groups similar to those... 

Ethylcyclohexene, 209 Ethyl diazoacetate, 137, 138—139, 210 Ethyl dibromoacetate, 26, 28, 236 Ethyl dichloroacetate, 26 Ethyl tram,cis,irans-3,1 l-dimethyl-7-ethyl-trideca-2,6,10-trienoate, 110 Ethyl diphenylphosphonite, 139—140 Ethylene chlorohydrin, 272 Ethylenediamine, 57 Ethylene dibromide, 159 Ethylene glycol, 274 Ethyleneketals, 140 Ethylene oxide, 140 Ethyl farnesoate, 110 Ethyl 3-hexenoate, 236 Ethyl 3-hydroxybutanoate, 310 Ethyl 3-hydroxy-3-methylbutyrate, 118 9-Ethylidenefluorene, 35 Ethylidene iodide, 141... 

Ethylidene iodide-Diethylzinc, 141 Ethylidenetriphenylphosphorane, 141—142 Ethyliodomethylzinc, 257-258 Ethyl 1-naphthylacetate, 74 N-Ethyl-N-nitrosourea, 73... 

CARBENES, GENERATION Chloral. Dibromofluoromethane. Dimethoxy-methyl)trimethoxysilane. Dimethyl diazomethylphosphonate. S -Dimethyl-N-nitroso-2-oxazolidone. Ethylidene iodide-Diethylzinc. Ethyl trichloroacetate. Phenyl(dibromochloro methyl) mercury. Phenyl(dihalocarbomethoxymethyl)mer-cury. Phenyl(trifluoromethyl)mercury. Phenyl(trihalomethyl)mercury. Sodium chlorodiiluoroacetate. Zinc powder. 

Acetylene reacts with iodine which has been covered with alcohol, and forms a di-iodide,C2H2I2. Acetylene does not appear to unite directly with hydrochloric acid with concentrated hydrobromic acid at 100° a reaction takes place slowly, and one molecule of the hydrocarbon and one of the halogen acid unite and form bromoethylene, H2C = CHBr. Under similar conditions with hydriodic acid, iodo-ethylene, H2C = CHI, and ethylidene iodide, CH3CHI2, are formed. Acetylene and hydrogen unite in the presence of finely-divided platinum to form ethane. 

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