4-亞苄基-2,2,5,5-四甲基氢化呋喃酮-3的若干反应

SOME REACTIONS OF 4-BENZILIDENE-2, 2, 5, 5-TETRAMETHYL-TETRAHYDROFURANONE-3

1) 4-苯甲酰基-2,2,5,5-四甲基氢化呋喃酮-3(Ⅲ)不能由相应的氢化呋喃酮与苯甲酸酯缩合而得,但可通过呋喃酮与苯甲醛缩合产物与溴加成,然后再经醇钠作用而得。 2) 二溴化物(Ⅱ)对热不稳定,与环己胺或吡啶作用时能脱去一分子溴而生成α,β-不饱和酮(Ⅰ),与氢化吡啶作用时除(Ⅰ)外还生成产物(Ⅳ)。 3) α,β-不饱和酮(Ⅰ)与氢化吡啶或吗福林进行加成,得到相应的产物(V_a)与(V_b)。

(1) 2, 2, 5, 5-tetramethyl-tetrahydrofuranone-3 does not condense in the presence of sodium ethoxide with ethyl benzoate to give the expected 4-benzoyl-2, 2, 5, 5-tetramethyl-tetrahydro-fnranone-3. This expected compound is obtained by the addition of bromine to 4-benzilidene-2, 2, 5, 5-tetramethyl-tetrahydrofuran-one-3 and subsequent treatment of the dibromo compound so obtained with sodium ethoxide. (2) On heating or on treating with cyclohexylamlne or pyridine, the dibromide (Ⅱ) loses one molecule of bromine, reverting to the unsaturated ketone (Ⅰ). The reaction between the dibromide and piperidine yields a mixture of compounds (Ⅰ) and (Ⅴ). (3) Addition oF piperidino or morpholine to the a, β-unsaturated ketone (Ⅰ) leads to products (Ⅴa) and (Ⅴb) respectively.