Syntheses of tetrahydrofurobenzofurans and dihydromethanobenzodioxepines from 5-hydroxy-3-methyl-3H-benzofuran-2-one. Rearrangement and ring expansion under reductive conditions on treatment with hydrides.
Syntheses of tetrahydrofurobenzofurans and dihydromethanobenzodioxepines from 5-hydroxy-3-methyl-3H-benzofuran-2-one. Rearrangement and ring expansion under reductive conditions on treatment with hydrides.
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由 5-羟基-3-甲基-3H-苯并呋喃-2-酮合成四氢呋喃苯并呋喃和二氢甲烷苯并二氧杂环己烷。
DOI：
10.1021/jo0503052
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Brossi,Arnold
中科院分区：
文献类型：
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作者：
Luo,Weiming;Yu,Qian-Sheng;Holloway,HaroldW;Parrish,Damon;Greig,NigelH;Brossi,Arnold
以5-羟基-3-甲基-3H-苯并呋喃-2-酮（5）为起始原料，制备了（±）-5-羟基-3a-甲基-2，3，3a，8a-四氢呋喃并[2，3-B]苯并呋喃（10）和（±）-7-羟基-5-甲基-4，5-二氢-2，5-亚甲基-1，3-苯并二氧杂环庚因（1,4）。初步研究了相对于5-羟基-3-甲氧羰基亚甲基-3-甲基-3H-苯并呋喃-2-酮6的反应性降低。同时，对10和14的形成提出了一个合理的机理，包括半缩醛15的环化、重排和扩环。酚类化合物10和14的特异性氨基甲酸酯对人乙酰胆碱酯酶（AChE）和丁酰胆碱酯酶（BChE）的体外抑制活性令人印象深刻。
5-Hydroxy-3-methyl-3H-benzofuran-2-one,5, easily obtained from pyruvic acid and 1,4-cyclohexanedione, was used as a starting material to prepare (±)-5-hydroxy-3a-methyl-2,3,3a,8a-tetrahydro-furo[2,3-b]benzofuran,10, and (±)-7-hydroxy-5-methyl-4,5-dihydro-2,5-methano-1,3-benzodioxepine,14. Reduced reactivity relative to 5-hydroxy-3-methoxycarbonylmethylene-3-methyl-3H-benzofuran-2-one,6, was preliminarily studied. Meanwhile, a plausible mechanism with regard to the formation of10and14, which included cyclization, rearrangement, and ring expansion of hemiacetal,15, is proposed. Specific carbamates of phenols,10and14, have shown impressive inhibitory activities against human acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) ex vivo.