Isomerization chloride

Treatment of 3 methyl 2 butanol with hydrogen chloride yielded only a trace of 2 chloro 3 methylbutane An isomeric chloride was isolated in 97% yield Suggest a reasonable structure for this product... 

Shimizu and co-workers reported that thermal decomposition of A4-thiabenzenes ylides afforded both thienofuran and thiophene derivatives in addition to the expected alkyl-rearranged products. A plausible mechanism was proposed with a [3.1.0] bicyclic sulfonium salt 9 as the key reactive intermediate <2001J(P1)2269>. Warren and co-workers, in their study of stereospecific phenysulfanyl migrations, found that [l,4]-sulfanyl participation could compete with the usual [l,2]-sulfanyl participation <1999SL1211>. Rearrangement of alcohol 18 with TsCl in pyridine gave an inseparable mixture of isomeric chlorides, 19 and 20, in a ratio of 52 48, as shown in Equation (3). 

As purchased from the Aldrich Chemical Company, inc., this chloride contains 5-10% of 1-chloro-1-methyl-3-butene. Contamination by this isomeric chloride does not affect the yield of tributyl(3-methyi-2-butenyl)tin. 

The formation of both isomeric chlorides 147 and 148 and the corresponding methoxy adducts 149 and 150 in methanol is at variance with the behavior observed in AcOH/ LiC104, where only the acetoxy species 140 is formed. This has been interpreted by taking into account the possible role of a specifically solvated carbenium ion pair, such as 145, prior to the formation of a free carbenium ion of type 144. 

A comparison of these formula) with those of lactic and para lactic acids (p. 827) shows at a glance that No. 1 is the chloropropionie acid which yields lactic acid, whilst No. 2 is iso cbloropropiouic acid, which, by the substitution of its chlorine by hydroxyl, must yield pathetic acid. By the action of nascent hydrogen, both isomeric chlorides will obviously produce the same propionic acid. 

The compounds of molecular formula C4H9C1 are the isomeric chlorides butyl, isobutyl, sec-butyl, and te/T-butyl chloride. 

Secondary ethers of the type ArOCH(R)CH=CH2, where R is ethyl or n-propyl,are prepared from the chlorides instead of the bromides6-4 -41 62 because the isomeric chlorides C1CH(R)CH=CH2 and RCH=CHCH2C1 can be separated by distillation.96 The corresponding primary and secondary bromides are in very mobile equilibrium,97- 98 and, although... 

Butenyl Radicals. Walling and Thaler have shown that the free butenyl radicals formed in chlorinating butenes by tert-huty hypochlorite are configurationally stable (57) ds-2-butene yielded no trans-2-butenyl chloride, and trans-2-hutene yielded no ds-2-butenyl chloride. Thus, hydrogen transfer from hydrido complex to butenyl radicals may account for the partial retention of structure observed in the reduction of butenyl chlorides (Table II). Menapace and Kuivila likewise postulate the formation of such radicals as intermediates in the reduction of the isomeric chlorides with triphenyltin hydride (26). 

Castro and Kray have reduced the isomeric butenyl chlorides, using chromous sulfate (5). Again, allylic radicals were proposed as intermediates in the reaction. However, unlike the tin hydride reductions, 1-butene was obtained almost exclusively from each of the isomeric chlorides. The process has been described as occurring within a chromium complex. The preponderant formation of 1-butene from butenyl metal complexes has also been noted by others (12, 23, 46). 

PROBLEM 6.5 Addition of hydrogen chloride to 3,3-dimethyl-1-butene gives a mixture of two isomeric chlorides in approximately equal amounts. Suggest reasonable structures for these two compounds, and offer a mechanistic explanation for their formation. 

Isomeric chlorides which have the unsymmetrical structure (formula 1) and the symmetrical structure (formula 2) have been isolated in the case of certain other dibasic acids. 

Acid-catalyzed intramolecular addition of the free HS-group of the mercaptane 177 to the double bond C(6)-C(7) yielded almost quantitatively the tricyclic compound 179. Treatment of it with HCl/ethanol gave the corresponding ketal 180, with thio-nylchloride the two isomeric chlorides 181 (isotwistane-derivative) and 184 (bicyclo-... 

The complex isolated from the reaction of crotyl bromide with pentacyano-cobaltate(II) undergoes the same reactions with hydrido complex and acid as that isolated from butadiene 2. Reduction of a- and y-methylallyl chlorides yields the same distribution of butene isomers as obtained from butadiene. Treatment of these isomeric chlorides with pentacyanocobaltate(II) in the absence of hydrogen yields equal quantities of butadiene and butenes. 

In practice, three of the isomeric chloride ion complexes, characterised structurally, resulted from templated syntheses on the smaller chloride anion. The fourth isomer (a), with all phenyl substituents residing on the same side of the metal-lamacrocycle, does not form due to steric constraints. When the larger iodide ion was employed to template the formation of the tetrameric metallamacrocycle, the only stereoisomer formed was (c), with the alternating up down arrangement of phenyl groups. The steric interactions between I and the phenyl substituents are believed to be minimised in the transition state, leading to the formation of this stereoisomer to an extent which is not possible in the transition states for the formation of other three stereoisomers [47, 48],... 

The solvolysis of 3-chloro-3-methyl- 1-butene in acetic acid at 25 C gives initially a mixture containing mostly the structurally isomeric chloride with some of the acetate. After a longer period of time, no allylic chloride remains and the acetate is the only product present. Explain this result. 

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