Transannular Proton Transfer in the Cyclization of Geranylgeranyl Diphosphate to Fusicoccadiene, a Biosynthetic Intermediate of Fusicoccins

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• 作者：Tomonobu Toyomasu ; Mai Tsukahara ; Hiromichi Kenmoku ; Masahide Anada ; Hajime Nitta ; Junko Ohkanda ; Wataru Mitsuhashi ; Takeshi Sassa ; Nobuo Kato
• 刊名：Organic Letters
• 出版年：2009
• 出版时间：July 16, 2009
• 年：2009
• 卷：11
• 期：14
• 页码：3044-3047
• 全文大小：267K
• 年卷期：v.11,no.14(July 16, 2009)
• ISSN：1523-7052

文摘

Enzymatic cyclization of geranylgeranyl diphosphate to fusicoccadiene involves a transannular proton transfer process. Label distribution in the cyclized products derived from deuterium-labeled GGDPs showed that a proton generated from C-10 migrates to C-6 in the intermediary dolabellane framework prior to the second ring formation. Although a direct 1,5-proton transfer would achieve this process, semiempirical MO calculations suggested an alternative pathway, which involves successive 1,4- and 1,5-proton transfers using C-2 as a springboard.