Acetate solvolysis

Benzo[h]tellurienylethyl acetate solvolysis, 4, 952 Benzo[h]tellurophene, 3-bromo-synthesis, 4, 954 Benzo[h]tellurophene, 3-chloro-synthesis, 4, 954... 

In all four reactions in which the reactivities of both positions in furan and thiophene have been determined under the same conditions (pyrolysis of 1-arylethyl acetates, solvolysis of I-arylethyl acetates, proti-odesilylation, and protiodeboronation), the reactivity order is the same 2-furan > 2-thiophene > 3-furan > 3-thiophene. In two other reactions, the order 3-thiophene > 3-furan appears to be obtained. However, in the solvolysis of 1-arylethyl p-nitrobenzoates, these esters were measured neither relative to each other nor to a standard compound (nor by the same worker), and the conclusion is almost certainly in error. Likewise in acetylation, the low reactivity of the 3-position of furan (which also shows up in the 2-isomer) is attributable to coordination with the Lewis acid catalyst. 

Aromatic Trifluoro acetylation" Formylation Solvolysis of 1-arylethyl acetates Solvolysis of 1-arylethyl p-nitrobenzoates... 

The difference in the rate of benzoate and acetate solvolysis is sufficient to enable selective removal of acetates in the presence of benzoates. Typical conditions include magnesium methoxide in methanol [Scheme 4.336],608 guanidine in methanol-dichloromethane,610 and fluoroboric acid in methanol.638 Fluorine substitution on benzoyl groups increases hydrolytic lability.63 ... 

Due to the strain imposed by the three-membered ring, the cyclopropyl cation is not a stable intermediate and electrocyclic ring opening occurs readily. Therefore, in the solvolysis of cyclopropyl tosylate in acetic acid, allyl acetate is obtained rather than cyclopropyl acetate. Solvolysis reactions of other cyclopropyl halides, sulphonates, and diazotization of cyclopropylamine in aqueous solution also give the allylic products. 

Recently, the solvolysis of ferrocenylmethyl acetate has been studied in 2,2,2-trifluoroethanol (TFE)-ethanol mixtures and in aqueous ethanol, acetone, and TFE. " For 19 solvents, a fair correlation with OTs values has been obtained. This correlation was much improved when OTs values were replaced with the derived solvent ionizing power (Foac) values. The latter correlation, with a slope close to unity, supported the S l assignment for ferrocenylmethyl acetate solvolyses. The same authors obtained an excellent correlation against their Foac values for a-ferrocenylethyl acetate solvolysis, as well. Since it had previously been shown that the introduction of an a-methyl group into fer-... 

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