(89%). Diels-Alder cycloaddition reactions of furan 2 with the alkynes CF3CCCF3 (100 °C), 1 (100 °C) and MeO2CCCCO2Me (120 °C) in solvent CH2Cl2 afford the 1:1 adducts 13 (95%), 14 (47%) plus 15 (45%), and 16 (92%), respectively, but reaction with ethyl propynoate does not take place at or below 120 °C and at 150 °C a complex product mixture is obtained. The 1:1 adduct 3 undergoes reaction with triflic
呋喃与4,4,4-三
氟丁-2-酸
乙酯(1)(摩尔比为1.2:1)在40°C的真空下反应,得到1:1加成的氧杂降
冰片二烯(3)(70%)和2 :1加成物(5)为内向异构体(5a)(16%)和外向异构体(5b)(10%)的异构体;在20℃下,使用过量的酯1,将1:1加合物3的收率提高至93%。1:1的加合物3催化加氢()并控制氢的吸收,从而生成氧杂
硼硼烷9(89%)或氧杂
降冰片烯10(90%),并进行化合物10的流热解在氮气中400℃下,得到3-羧乙氧基-4-三
氟甲基
呋喃(2)(89%)。的
呋喃狄尔斯-阿尔德环加成反应2与
炔烃CF 3 CCCF 3(100℃),1(100℃)和的MeO 2 CCCCO 2我(120℃)在溶剂CH 2
氯2得到1:1的加合物分别为13(95%),14(47%)加15(45%)和16(92%),但在120°C或更低温度和150°C或更低温度下不会与
丙酸乙酯发生反