Hydro-acyloxy-addition

Addition of Carboxylic Acids Hydro-acyloxy-addition... 

In view of the feet that complete removal of water vapor cannot be readily achieved, we prepared water-free bulk and silica-supported zirconium sulfate. The bulk anhydrous Zr(S04)2 was obtained by reaction of zirconium tetrachloride with oleum [1]. The silica-supported zirconium sul te resulted from deposition-precipitation of zirconium hydroxide on silica, calcination at 723 K and subsequent reaction with gaseous sulfur trioxide. The catalytic activity of the sul ted zirconia s was measured in the gas-phase /rora-alkylation of benzene (1) with diethylbenzene (2) to ethylbenzene (3, reaction 1) [8,9] and the liquid-phase hydro-acyloxy-addition reaction of acetic acid (4) and camphene (5) to isobomyl acetate (6, reaction 2) [8,10]. With the /roras-alkylation we used an amorphous silica-aliunina catalyst as a reference. 

Liquid-phase hydro-acyloxy-addition of acetic acid (4) to camphene(S)... 

Fig. 5. Course of the reaction to isobomyl acetate (6) by the hydro-acyloxy-addition of 0.70 mol acetic acid (4) to 0.70 mol camphene (5) at 338 K (stirred tank reactor, N2 atmosphere). O 2.5 g %O IZxO ll Si02 without H2O and 2.5 g S03/Zr02/Si02 and 320 ml (17.78 mmol) H2O.

In the previous edition of EIC, Larock described in detail the hydro-, aUcoxo-, peroxo-, and acyloxy-mercuration of olefins. These reactions generally proceed in a Markovnikov fashion yielding products of anti addition, although in some cases (e.g. 

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