Limonene dioxide is a platform molecule for the production of new biopolymers. First attempts at limonene epoxidation were made by using low-coordination titanium supported on SBA-16 as the catalyst using tert-butyl hydroperoxide as the oxidizing agent, but no limonene dioxide was obtained. When limonene was substituted by 1,2-limonene oxide, the yield of limonene dioxide was only 13% in the same conditions. Two other techniques, both using in situ generated dimethyl dioxirane by the reaction of acetone with Oxone, have been studied and compared. These reactions are carried out in semibatch conditions and at room temperature. The first double epoxidation of limonene was performed in a conventional biphasic organic–water system and the other in excess acetone. The former epoxidation of limonene using ethyl acetate as the organic phase allowed reaching 95% conversion and yielding 33% of limonene dioxide. In comparison, when the reaction was performed in acetone, a limonene dioxide yield of 97% was observed under optimized conditions. The double epoxidation of limonene should be carried out at room temperature with a flowrate of 4 mL min^–1 of aqueous Oxone for a period of 45 min with a stoichiometric excess of 30% of Oxone.

中文翻译：

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柠檬烯无催化剂环氧化为氧化二烯

二氧化柠檬烯是用于生产新型生物聚合物的平台分子。在环氧化柠檬烯首先尝试通过使用低协调钛制成使用支撑在SBA-16作为催化剂叔丁基过氧化氢作为氧化剂，但未获得二氧化烯。当将柠檬烯用1，2-柠檬烯氧化物代替时，在相同条件下，柠檬烯二氧化物的收率仅为13％。已经研究和比较了两种其他技术，它们都是通过丙酮与Oxone反应原位生成的二甲基二环氧乙烷。这些反应在半间歇条件和室温下进行。柠檬烯的第一次双环氧化是在常规的双相有机-水系统中进行的，另一次是在过量的丙酮中进行的。柠檬烯的前环氧化反应使用乙酸乙酯作为有机相，可以实现95％的转化率，并产生33％的二烯柠檬烯。相比之下，当反应在丙酮中进行时，在最佳条件下观察到二氧化烯的产率为97％。^–1的Oxone水溶液持续45分钟，化学计量过量的Oxone为30％。