Efficient Enantioselective Hetero-Diels-Alder Reaction of Brassard's Diene with Aliphatic Aldehydes: A One-Step Synthesis of (R)-(+)-Kavain and (S)-(+)-Dihydrokavain

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• 作者：Lili Lin ; Zhenling Chen ; Xu Yang ; Xiaohua Liu ; Xiaoming Feng
• 刊名：Organic Letters
• 出版年：2008
• 出版时间：March 20, 2008
• 年：2008
• 卷：10
• 期：6
• 页码：1311 - 1314
• 全文大小：75K
• 年卷期：v.10,no.6(March 20, 2008)
• ISSN：1523-7052

文摘

An efficient catalytic asymmetric hetero-Diels-Alder reaction of Brassard's diene with aliphatic aldehydes was reported. The catalyst, whichwas generated from (R)-BINOL, Ti(i-PrO)₄, and 4-picolyl chloride hydrochloride, promoted the reaction smoothly to afford the corresponding,-unsaturated -lactone derivatives in moderate-to-good yields (46-79%) with high enantioselectivities (up to 88% ee). Natural products(R)-(+)-kavain (70% ee, >99% ee after single recrystallization) and (S)-(+)-dihydrokavain (84% ee) were also prepared in one step by using thismethodology.