Tandem Wittig–intramolecular Diels–Alder cycloaddition of ester-tethered 1,3,9-decatrienes under microwave heating

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• 作者：Jinlong Wu ; Xiuqing Jiang ; Jingjing Xu ; Wei-Min Dai
• 关键词：1 ; 3 ; 9-Decatriene ; Intramolecular Diels– ; Alder cycloaddition ; Microwave ; 1-Oxo-3 ; 4 ; 4a ; 7 ; 8 ; 8a-hexahydro-1H-isochromene ; Wittig olefination
• 刊名：Tetrahedron
• 出版年：2011
• 出版时间：7 January 2011
• 年：2011
• 卷：67
• 期：1
• 页码：179-192
• 全文大小：610 K

文摘

Intramolecular Diels–Alder (IMDA) cycloaddition of the ester-tethered 1,3,9,-decatrienes possessing a carbonyl substituent at C10 has been investigated under controlled microwave heating (MeCN, 180 °C) to afford a variety of 3,4,4a,7,8,8a-hexahydroisochromen-1-ones in 53–89 % yields and in 64:36–79:21 ratios for the cis and trans isomers. Under the same microwave heating conditions, a tandem Wittig–IMDA cycloaddition, starting from the α-bromoacetates of 3,5-hexadien-1-ols and glyoxalate/phenylglyoxal hydrates in the presence of PPh₃ and 2,6-lutidine, has been demonstrated, furnishing 3,4,4a,7,8,8a-hexahydroisochromen-1-one adducts in 73–91 % yields in favor of the cis isomers. During this tandem process, three consecutive carbon–carbon bonds in the end products were efficiently formed with the aid of microwave irradiation within short reaction times.