A novel and efficient p-TsOH-promoted cascade cyclization of 2-propynolphenols is developed to give 4-tosyloxy-2H-chromenes in moderate to efficient yields. It is noted that p-TsOH acts not only as a promoter in this reaction, and also as the sulfonate source. Importantly, the obtained 4-tosyloxy-2H-chromenes can be used as versatile intermediates for the synthesis of various functionalized compounds
                                    开发了新颖且有效的2-
丙炔酚酚的p -TsOH-促进的级联环化反应,以中等至有效的产率得到4-
甲苯磺酰氧基-2 H-色烯。应当指出,对-TsOH不仅在该反应中起
促进剂的作用,而且还起
磺酸盐源的作用。重要的是,所获得的4-
甲苯磺酰氧基-2 H-色烯可以用作通过各种
金属催化的交叉偶联反应合成各种官能化化合物的通用中间体。而且,该方法可以扩大到克级。