Hydrogen peroxide propylene oxide synthesis

The yields shown by Table II are somewhat lower than those alreatfy reported for the propylene oxide synthesis using preformed hydrogen peroxide (12). However, due to the preliminary nature of the experiments carried out... 

The study of the substrateireagent ratio (Figure 7.6) on the synthesis rate of propylene oxide promoted determination of optimal molar ratio C3H6 H202 = 1 1. As combined with the propylene conversion level exceeding 90%, this indicates the stoichiometric type of interaction between them. This circumstance confirms substrate oxidation with hydrogen peroxide by the heterolytic mechanism. 

Figure 7.10 The mechanism of allyl alcohol synthesis in propylene oxidation with hydrogen peroxide, in the presence of PPFe3+0H/Al203.

Figure 7.14 The mechanism of propionic aldehyde synthesis at propylene oxidation with hydrogen peroxide on PPFe3+0H/Al203 catalyst.

New synthetic processes for the preparation of established products were also industrially developed in Japan the manufacture of methyl methacrylate from C4 olefins, by Sumitomo and Nippon Shokubai in France, the simultaneous production of hydroquinone and pyro-catechin through hydrogen peroxide oxidation of phenol by Rhone-Poulenc in the United States the production of propylene oxide through direct oxidation of propylene operating jointly with styrene production, developed by Ralph Landau and used in the Oxirane subsidiary with Arco, which the latter fully took over in 1980 in Germany and Switzerland, the synthesis of vitamin A from terpenes, used by BASF and Hoffmann-La Roche. 

M. G. Clerici, G. Bellussi, U. Romano, Synthesis of propylene oxide from propylene and hydrogen peroxide catalyzed by titanium silicalite, J. Catal. 129 (1991) 159. 

By far the most concise synthesis of 1 has arisen from the work of Schreiber in 1980 (see Scheme 1.8). The lithium enolate 28 was monoalkylated with propylene oxide in the presence of trimethyl aluminum to give keto alcohol 29 in 96% yield (based on recovered 28). The addition of hydrogen peroxide under acidic conditions then made available the hydroperoxide 30 in 99% yield. A ferrous-ion-induced fragmentation then gave the natural product 1 in 96% yield as a single olefin isomer. 

Prevention of so-called co-products by direct synthesis, for example of propylene oxide or hydrogen peroxide. 

New routes to hydrogen peroxide new methods for direct synthesis of hydrogen peroxide (from hydrogen and oxygen) in a controlled, safe manner could provide a lower cost oxidant that reduces the use of chlorine. For example, in situ generation of hydrogen peroxide can be used to produce propylene oxide in place of the chlorohydrin route and... 

Clerid, M., BeUussi, G. and Romano, U. (1991). Synthesis of Propylene Oxide from Propylene and Hydrogen Peroxide Catalyzed by Titaninm Silicalite, J. Catal., 129, pp. 159-167. 

Oxirans.—A simple four-stage preparation of (5)-propylene oxide from ethyl L-( —)-maleate has been described (Scheme 2). This work is of importance for the synthesis of nonactin carboxylic acid. Another synthesis of optically-active propylene oxide involves the cyclization of OL-propylene chlorohydrin with a variety of bases in the presence of a cobalt complex the highest optical purity was 27%. Wynberg and co-workers have shown that the base-catalysed epoxidation of electron-poor alkenes is subject to catalytic asymmetric induction hydrogen peroxide and t-butyl hydroperoxide were used as oxidants in the presence of quaternary... 

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