Ring-Opening Reactions of 伪- and 尾-Pinenes in Pressurized Hot Water in the Absence of Any Additive

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• 作者：Tomomi Kawahara ; Yui Henmi ; Natsu Onda ; Toshiyuki Sato ; Akiko Kawai-Nakamura ; Kiwamu Sue ; Hiizu Iwamura ; Toshihiko Hiaki
• 刊名：Organic Process Research & Development
• 出版年：2013
• 出版时间：December 20, 2013
• 年：2013
• 卷：17
• 期：12
• 页码：1485-1491
• 全文大小：310K
• 年卷期：v.17,no.12(December 20, 2013)
• ISSN：1520-586X

文摘

Reactions of 伪- and 尾-pinenes in pressurized hot water were examined in a batch reactor made of a SS316 1/2-in. tube at temperatures of 250鈥?00 掳C, pressures of 4鈥?0 MPa, and reaction times of 1鈥?0 min in the absence of any additive under an argon atmosphere. The maximum yields of limonene from 伪-pinene were ca. 70% in 20 min at 300 掳C or 1 min at 400 掳C. Limonene was obtained from 尾-pinene in ca. 16% yield for 30 min at 300 掳C and 1 min at 400 掳C. Reversible production of myrcene in 14% yield and formation of unidentified C₂₀ dimer fractions were noted for 1 min at 370 掳C from 尾-pinene. The conversion of 伪-pinene to limonene took place under anhydrous conditions, albeit at slightly lower yield of 65% compared to processes conducted in the presence of water, where increased limonene yield of 70% was observed for 1 min at 400 掳C. The conversion of 尾-pinene to limonene under anhydrous conditions was limited to 6.1% in contrast to 11.9% in the presence of water for 7 min at 370 掳C. In the presence of oxygen, p-cymene was formed in 23% and 24% yield at the expense of limonene from 伪- and 尾-pinenes, respectively, for 30 min at 400 掳C.