step by cyclocondensation of 1,3‐diketone dianions with aldehydes. The use of HCl (10%) for the aqueous workup proved to be very important to avoid elimination reactions of the 5‐aryl‐5‐hydroxy 1,3‐diones formed as intermediates. The TiCl4‐mediated cyclization of a 2‐aryl‐2,3‐dihydro‐4H‐pyran‐4‐one with 1,3‐silyloxybuta‐1,3‐diene resulted in cleavage of the pyranone moiety and formation of a highly functionalized
2-芳基-2,3-二氢-4- ħ -
吡喃-4-酮是在一个步骤中通过与醛1,3-二
酮酸根环化缩合制备。事实证明,在
水溶液处理中使用HCl(10%)对于避免形成中间体的5-芳基-5-羟基1,3-二酮消除反应非常重要。TiCl 4介导的2-芳基-2-3,3-二氢-4 H-
吡喃-4-酮与1,3-甲
硅烷基氧基丁-1,3-二烯的环化反应导致
吡喃酮部分裂解并形成高官能化苯衍
生物。