Efficient enantioselective hetero-Diels-Alder reaction of Brassard's diene with aliphatic aldehydes:: A one-step synthesis of (R)-(+)-kavain and (S)-(+)-dihydrokavain
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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DOI：
10.1021/ol8002282
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发表时间：
2008-03-20
期刊：
影响因子：
5.2
通讯作者：
Feng, Xiaoming
中科院分区：
文献类型：
--
作者：
Lin, Lili;Chen, Zhenling;Feng, Xiaoming
报道了Brassard's二烯与脂肪醛的高效催化不对称异diels - alder反应。该催化剂由(R)-BINOL、Ti(i-PrO)(4)和4-吡咯酰氯盐酸盐合成，可顺利促进反应生成相应的α、β -不饱和δ -内酯衍生物，产率为中优（46-79%），对映选择性高（高达88% ee）。用该方法一步制得天然产物(R)-(+)-kavain （70% ee, > - 99% ee）和(S)-(+)-二氢kavain （84% ee）。
An efficient catalytic asymmetric hetero-Diels-Alder reaction of Brassard's diene with aliphatic aldehydes was reported. The catalyst, which was generated from (R)-BINOL, Ti(i-PrO)(4), and 4-picolyl chloride hydrochloride, promoted the reaction smoothly to afford the corresponding alpha,beta-unsaturated delta-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 this methodology.