Formation and Reaction of Carbonyl Ylides. Reactions of 1-Methoxy-2-benzopyrylium-4-olate with Isothiocyanates
作者:Toshikazu Ibata、Hirofumi Nakano、Hatsue Tamura
DOI:10.1246/bcsj.65.1362
日期:1992.5
cycloadducts of each previous steps. The molecular structure of the 2 : 1-adduct of 2 with phenyl isothiocyanate was determined by means of X-ray crystallography. Colorless crystals of the adduct are monoclinic with the space group P21/a, and with the unit-cell dimensions of a = 12.619 (4), b = 16.432 (4), c = 11.238 (2) A, β = 97.39 (1)°, and Z = 4. The structure was calculated by direct methods (MULTAN 80)
通过 Cu(acac)2-催化分解 2-重氮乙酰基苯甲酸甲酯与各种异硫氰酸芳基酯和异硫氰酸甲酯产生 1-甲氧基-2-苯并吡喃-4-醇酸 (2) 的 1,3-偶极环加成反应得到 2:1-, 3:1-、4:1-和 5:1-加合物而不提供 1:1-加合物。2 的第一次环加成发生在异硫氰酸酯的 C=N 双键上。以下步骤的环加成,例如第二、第三、第四和第五环加成,在每个先前步骤的环加成物的 C=O 基团上进行。2与异硫氰酸苯酯的2:1-加合物的分子结构通过X-射线晶体学测定。加合物的无色晶体是单斜晶系,空间群为 P21/a,晶胞尺寸 a = 12.619 (4), b = 16.432 (4), c = 11.238 (2) A, β = 97.39 (1 )°,Z = 4。结构通过直接方法 (MULTAN 80) 计算并通过块对角最小二乘法进行细化。所有的氢原子都是通过差分傅立叶同步...