Study on Photoreaction of 2-(4'-Methoxy-)trans-sstyrylthiophene and It's Derivatives

• Main Author: 施勝鈶
• Other Authors: 何東英
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/68675762412630213831

碩士 === 國立臺灣大學 === 化學學系 === 83 === 　　In the presence of iodine, 2-(4'-methoxy- )trans- styrylthiophene (1) reacted and produced 6-methoxynaphtho(3,4,b) thiophene(1c) under the ultraviolet radiation; the similar reaction as stilbene reacted under the ultraviolet radiation. If there was no any oxidative reagent in the solution, we got 4-(5'-benzothiophenyl-)trans. -3-buten-2-one(la) which rearranged from compound (1). We thought that the conjugated intermediate of dihydronaphthothiophene(18) was produced and than a proton shifted、opened the ring、left a carbene, and got compound (1a). The same reactions happened when 3-(4'-methoxy-)-trans-styryl- thiophene(2)、2 or 3-(4'-methoxy-)-trans-styrylfuran(3 or 4)、2-(4'-methoxy)trans-styryl-N- methylpyrrole(5) were radiated by ulraviolet radiation, and we would get 4-(6'-benzothiophenyl-)rans-3-buted-2-one (2a)、4-(5'-benzofuryl-)-trans-3- buten-2-one (3a)、4-(6'-benzofuryl-) trans-3-buten-2-one(4a) and 4-(N'-methyl-5'-benzopyrrolyl-)trans-3-buten- 2-one(5a). It was interesting that 2-(4'-methoxy-)-trans-styryl-3-methyl thiophene(6) did not react the same photoreaction. We thought that the methyl-shift was diffcult than the proton-shift, so it would go to the different reaction pathway and produce 2-(4'-hydroxy-)trans-styrylthiophene(6a) and traced amount of 4-5'-2'- methylbenzothiophenyl-) trans-3- buten-2- one(6b).