Hydrolysis of an Allylic Halide

Hydrolysis of an Allylic Halide (3-Chloro-3-methyl-l-butene) THE OVERALL REACTION  

Step 1 The alkyl halide ionizes to give a carbocation. This step is rate-determining. 

The positive charge in the 1,1-dimethylallyl cation is shared between two allylic carbons. 

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Reaction of an allylic halide such as A with N-cyanomethylpyrrolidine, followed by treatment with potassium t-butoxide and then aqueous hydrolysis, is a... 

Treat this 8-ketoester with one equivalent of sodium ethoxide to form an anion followed by alkylation of the anion with one equivalent of an allyl halide. Subsequent hydrolysis of the ester in aqueous base followed by acidification and thermal decarboxylation gives the desired product. 

Treatment with BuLi generates chemoselectively the lithium enolate of the less substituted lactim and electrophiles attack the face opposite the branched isopropyl group. Selectivity is good the purified diastereoisomers can be isolated in over 80% yield and hydrolysis requires only dilute aqueous acid as these are easily protonated imines. These examples show a benzylic and an allylic halide. The first 50a is unnatural (R) -phenylalanine and the second 50b is an unnatural amino acid. 

Organonickel(II) species are believed to be formed during the reaction between [Ni(TMC)] and primary alkyl halides, and subsequently undergo hydrolysis with cleavage of the Ni—C bond. Kinetic data measured in the presence of excess alkyl halide indicate a rate law -dlNi1 (TMC)+]/cft = MNi (TMCr][RX]. The rate constants increase for R and X in the order methyl < primary < secondary < allyl < benzyl halides and Cl < Br < I (133, 140). This suggests that the rate-determining step is electron transfer from the Ni(I) complex to R—X via an inner-sphere atom-transfer mechanism (143). 

If on the other hand the Sn2 reaction with cyanide is favoured, as with allylic 47 or benzylic 50 halides, that method is better.15 Hydrolysis of the nitrile 48 gives the acid 49 but treatment with an alcohol in acidic solution gives the ester 52 directly.16... 

Allyl silanes will also attack carbonyl compounds when they are activated by coordination of the carbonyl oxygen atom to a Lewis acid. The Lewis acid, usually a metal halide such as TiCLj or ZnCl2, activates the carbonyl compound by forming an oxonium ion with a metal-oxygen bond. The allyl silane attacks in the usual way and the (3-silyl cation is desilylated with the halide ion. Hydrolysis of the metal alkoxide gives a homoallylic alcohol. 

The acceleration of the 3-aza-Cope rearrangement of A-allylenamines through formation of a cationic quaternary nitrogen center (enammonium salt) has obvious advantages. However, direct allylation of enamines in order to form the enammonium ions is unsatisfactory, and difficult. Moreover, the rearrangement-hydrolysis product is often contaminated by the C-allylated product when an unsymmetrical allyl halide is employed... 

Both sides of acetone have been alkylated with different alkyl groups, in one operation, by treatment of the A, A -dimethylhydrazone of acetone with n-BuLi, followed by a primary alkyl, benzylic, or allylic bromide or iodide then another mole of n-BuLi, a second halide, and finally hydrolysis of the hydrazone. " Alkylation of an unsymmetrical ketone at the more substituted position was reported using an alkyl bromide, NaOH, and a calix[n]arene catalyst (see p. 122 for calixarenes). ... 

Hydrolysis of the reaction mixture afforded 63 in 80% yield as a single cis diastereomer, and the formation of cyclic organozinc bromide was checked by iodinolysis, by coupling reactions with vinyl iodides in the presence of a catalytic amount of Pd(PPh3)4, or by reaction with allyl halides after transmetallation of the organozinc bromide into an organocopper reagent [60] (Scheme 7-53). 

Alkylation of metallated a-(dialkylamino)nitriles with alkyl halides, epichlorohydrin, allyl halides or ethyl bromoacetate followed by hydrolysis furnishes an array of ketones in good yield. - For example, reaction of (42) with benzyl chloride leads to the formation of deoxybenzoins. Alkylation of a-(dialkyl-amino)nitriles is also possible if the latter are derived from aliphatic aldehydes. - ... 

Sturtz et al. have described the deprotonation of the allyl bis(dimethylamido)phosphonate (9). Treatment of (9) with two equivalents of base, followed by reaction with an epoxide and hydrolysis, yields the y-lactone (Scheme 10). Alkylation with alkyl and alkenyl halides occurs at the y-carbon and hydrolysis yields the saturated and unsaturated carboxylic acids respectively. 

The anion of the isoquinoline Reissert compound (26) has also been alkylated with a wide variety of other alkyl halides.519-35 38 48-62-66,90 93 The alkylation product from 26 and allyl chloride undergoes isomerization to 38 on base-catalyzed hydrolysis.90 The phthalazine Reissert compound (3) has also been alkylated, in the presence of sodium hydride, with methyl iodide39 and with benzyl halides40 to give, after hydrolysis, 1-substituted phthalazines. A phthalazine analog of 34 (n = 3) has been prepared.1511 An additional example of the alkylation of the quinoline Reissert compound in the 4-position has appeared.943... 

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