Chlorocyclohexane chloride

Chlorocyclohexane is converted into cyclohexane in dichloromethane using ethyldichlorosilane as reducing agent.192 The product yield is 40% with 25 mol% aluminum chloride and 45% with aluminum bromide. 1-Chloro-l-methylcyclohex-ane gives a 94% yield of methylcyclohexane using aluminum chloride and a 92% yield with aluminum bromide. Ethyldichlorosilane is superior as a hydride donor to either cumene or dicumylmethane.192... 

Problem 13.11 For the following pairs of halides and carbonyl compounds, give the structure of each alcohol formed by the Grignard reaction, (a) Bromobenzene and acetone, (b) p-Chlorophenol and formaldehyde, (c) Isopropyl chloride and benzaldehyde. (d) Chlorocyclohexane and methyl phenyl ketone. 4... 

A convenient method for the chlorofluorination of cyclohexene, with a mixture of lead(IV) acetate and anhydrous hydrogen fluoride in the presence of sodium or copper(II) chloride in 1,1,2-trichlorotrifluoroethane (Halon-113) at room temperature, has been described.22 The major product in this reaction is /ranj-l-chloro-2-fluorocyclohexane obtained in 70% yield. Byproducts are 2-chlorocyclohexanol and l-acetoxy-2-chlorocyclohexane which are obtained in 25 and 5 % yield, respectively. 

The free-radical-induced reaction of alkanes with sulfuryl chloride characteristically results in the chlorination of hydrocarbons. However, when pyridine is added to the irradiated reactants, sulfochlorination occurs in quite satisfactory yield. For example, the irradiated reaction of cyclohexane and sulfuryl chloride in the presence of pyridine resulted in a 54.8% yield of cyclohexanesulfonyl chloride and only 9.4% of chlorocyclohexane.161... 

When trans-1,2-cyclohexanediol is treated with equimolar TPP in excess CCI4, a 88% yield of trans-2-chlorocyclohexanol can be realized with no evidence ( 11, 1SC NMR, GLC) for trans-1.2-di-chlorocyclohexane or cis-2-chlorocyclohexanol. Since the trans chlorohydrin could not arise from simple displacement of TPPO by chloride ion with retention of stereochemistry (3), we suspected the intermediacy of cyclohexene oxide which could subsequently undergo ring opening by the hydrochloric acid (HC1) generated in solution. This was easily proven by repeating the reaction in the presence of solid potassium carbonate and realizing a 86% yield of cyclohexene oxide and no cis or trans chlorohydrins. 

When cyclohexene is treated with bromine in saturated aqueous sodium chloride, a mixture of trans-2-bromocyclohexanol and fraw.s-l-bromo-2-chlorocyclohexane results. Propose a mechanism to account for these two products. 

Cyclohexene is dissolved in a solution of lithium chloride in chloroform. To this solution is added one equivalent of bromine. The material isolated from this reaction contains primarily a mixture of trans- 1,2-dibromocyclohexane and trans-l-bromo-2-chlorocyclohexane. Propose a mechanism to show how these compounds are formed. 

Propose products (if any) and mechanisms for the following AlC -catalyzed reactions (a) chlorocyclohexane with benzene (b) methyl chloride with anisole (c) 3-chloro-2,2-dimethylbutane with isopropylbenzene... 

Formation of a C-C bond to a cyclopropane ring at the expense of a C-Si bond is also achieved by acetylation of trimethylsilylcyclopropanes. Cyclopropyltrimethylsilane was converted to acetylcyclopropane (5) in 60% yield when treated with a mixture of acetyl chloride and aluminum(III) chloride in dichloromethane. "- Other compounds subjected to the same reaction conditions involve various (n- -3)-trimethylsilylbicyclo[n.l.0]alkanes. Some of these compounds undergo ring opening and give no cyclopropane whereas others afford complex reaction mixtures. Thus, when cxo-6-trimethylsilylbicyclo[3.1.0]hexane was acetylated as outlined above a 55 35 6 4 mixture of 6-acetylbicyclo[3.1.0]hexane (6), l-(2-chlorocyclopen-tyl)-propan-2-one (7), 2-acetyl-l-chlorocyclohexane (8), and l-(cyclopent-l-enyl)propan-2-one (9), respectively, was isolated in 94% total yield. 

Modified Darzens reaction. The original Darzens synthesis of u./3-unxaturated ketones3 involved the addition of acid chlorides to cyclohexenes in the presence of aluminum chloride or stannic chloride followed by dehydrohalogenation. For example, the addition of acetyl chloride to cyclohexene affords l-acetyl-2-chlorocyclohexane, which on dehydrohalogenation (dimethylaniline) gives methyl cyclohexenyl ketone. 

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