Highly fluorinated heterocycles. Part XIX. Dehydrofluorination studies on 2-dipluoromethyl- and 2-trifluoromethyl-hexa- and -pentafluoro-oxolans
作者:James Burdon、Paul L. Coe、J.Anthony Smith、John Colin Tatlow
DOI:10.1016/s0022-1139(00)80133-5
日期:1991.4
The four 3H, 4H-2-difluoromethylpentafluoro-oxolans reacted with powderedpotassium hydroxide in suspension in benzene to give 3H- (1) and 4H- (2)2-difluoromethyltetrafluoro-3,4-oxolen, different proportions being formedfrom each stereoisomer. 3H/4H- and 4H/JH-2-Trifluoromethylpentafluoro-oxolanslikewise afforded different proportions of 3H- (3) and 4H- (4) 2-trifluoromethyltetrafluoro-3,4-oxolen.From
四种3H,4H-2-二氟甲基五氟-氧杂环戊烷与粉末状氢氧化钾在苯中的悬浮液反应,得到3H-(1)和4H-(2)2-二氟甲基四氟-3,4-二氧戊烯,每种立体异构体形成的比例不同。3H / 4H-和4H / JH-2-三氟甲基五氟-恶唑烷也同样提供了不同比例的3H-(3)和4H-(4)2-三氟甲基四氟-3,4-氧戊烯.3H-和4H-的混合异构体经过类似的脱氟化氢反应2-二氟甲基六氟-氧杂戊环,形成2-二氟甲基五氟-3,4-(5)和-2,3-(6)二氧戊环;混合3H-和4H-2-三氟甲基六氟-氧杂戊酸酯提供了不可分离的2-三氟甲基五氟-3,4-(7a)和-2,3-(7b)二氧戊环的混合物。与氟化钴一起,乙二醛(5)得到2-二氟甲基七氟-草索兰(8)。用氢氧化钾水溶液处理后,(8)开环,形成四氟戊-2-en-1,5-二醇酸(10)。Diels-Alder加合物是由环氧丙烷(Ta)与环戊二烯和呋喃反应制得的。