中文摘要：

发展了-条1，2,6，7．四氢-8H-茚并[5，4．6]呋喃-8-酮的新合成方法，以价廉、易得的对溴苯酚为原料，在无水碳酸钾作用下与2．溴乙醛缩二乙醇缩合后用多聚磷酸（PPA）环合得5-溴苯并呋喃，该中间体与丙烯酸甲酯在Pd（OAc）2催化下，经Heck偶合反应得3-（苯并呋喃-5-基）丙酸甲酯，在氢氧化钠水溶液中经RaneyNi催化氢化和水解-锅反应得3．（2，3．二氢苯并呋喃-5。基）丙酸，再经二溴代、Friedel—Crafts酰化反应和氢解脱溴，得1，2,6，7-四氢．8H-茚并[5，4—6．呋喃．8．酮，7步反应总收率49．9％．该方法原料易得、反应条件温和、操作简便、产物分离纯化容易，收率良好，适合大规模制备1267-四氢-8H-茚并[5,4-6]呋喃-8-酮．

英文摘要：

A novel process for synthesis of 1,2,6,7-tetrahydro-8H-indeno[5,4-b]furan-8-one, a key intermediate for prepara- tion of ramelteon, a MT1 and MT2 melatonin receptor selective agonist, was developed. The key intermediate 3-（2,3-dihydro- benzofuran-5-yl）propanoic acid was synthesized by condensation ofp-bromophenol with bromoacetaldehyde diethyl acetal in the presence of K2CO3 and Friedel-Crafts reaction to give 5-bromobenzofuran, which was subsequently subjected to Heck coupling reaction with methyl acrylate in the presence of palladium acetate, then catalytic hydrogenation and hydrolysis in one pot reaction. Subsequently, 1,2,6,7-tetrahydro-8H-indeno[5,4-b]furan-8-one was synthesized from 3-（2,3-dihydrobenzo- furan-5-yl）propanoic acid through bromination, Friedel-Crafts acylation and catalytic hydrogenolysis debromination. The overall yield was about 49.9%. The structures of intermediates and final product were determined by IH NMR, 13C NMR and HRMS techniques. This method has the advantages of easily available starting materials, simply conducted procedures, relatively high yield and easy purification, and is more suitable for scale-up production.