Carbonitriles and alcohols react in a Lewis acid-promoted Pinner reaction to carboxylic esters. Best results are obtained with two equivalents of trimethylsilyl triflate as Lewis acid. Good yields are achieved with primary alcohols and aliphatic or benzylic carbonitriles, but the straightforward synthesis of acrylates and benzoates starting with acrylonitrile and benzonitrile, respectively, is similarly possible. Phenols are not acylated under these reaction conditions. The method has been used for the first total synthesis of the natural product monaspilosin. In the reaction of benzyl alcohols variable amounts of amides are formed in a Ritter-type side reaction.
Carbonitriles和醇在Lewis酸促进的Pinner反应中反应生成
羧酸酯。最佳结果是使用两当量的三甲基
硅酰
三氟甲烷作为Lewis酸。一次醇和脂肪族或
苄基腈可以获得良好产率,但使用
丙烯腈和
苯甲腈分别合成
丙烯酸酯和
苯甲酸酯也同样可行。
苯酚在这些反应条件下不会酰化。该方法已被用于
天然产物单孢
氨基脂的首次全合成。在
苄醇的反应中,会形成不同量的酰胺,这是一种Ritter型的副反应。