Synthesis of polysubstituted furo[3,2-c]coumarins and polysubstituted naphtho[2,3-b]furan-4,9-diones via intramolecular Wittig reaction

• Main Authors: Zong-Ze Wu, 吳宗澤
• Other Authors: Wenwei Lin
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/05454314551540426926

碩士 === 國立臺灣師範大學 === 化學系 === 100 === 　　Furo[3,2-c]coumarin is one kind of the heterocyclic compounds abundant in nature. It has attracted scientists much attention because of its broad pharmacological activities. In 2010, our research reported a general preparation of tetrasubstituted furans via phosphorus zwitterions as key intermediates. Based on these observation, we want to develop a new synthetic protocol for the preparation of furo[3,2-c]coumarins using the corresponding stable phosphorus zwitterions. These new, stable phosphorus zwitterions can be prepared by our developed methodology starting from 4-hydroxy coumarin 13, the corresponding aldehydes 50, and tributylphosphine. All of the new type of phosphine zwitterions 48 can be generated in good yield (50-98%). The compounds 48 can be further acylated by the corresponding acid chlorides 51 and then deprotonated by triethylamine, and finally undergo intramolecular Wittig reactions to provide the corresponding highly functional furo[3,2-c]coumarins in good to high yield (61-99%).