Synthesis of dichloromethyl-substituted salicylates and pyran-4-ones by cyclocondensation of 1,3-bis(silyloxy)-1,3-butadienes with 1,1-dimethoxy-4,4-dichlorobut-1-en-3-one: control of the C,C- and C,O-regioselectivity by the choice of Lewis acid
作者:Vahuni Karapetyan、Satenik Mkrtchyan、Gagik Ghazaryan、Alexander Villinger、Christine Fischer、Peter Langer
DOI:10.1016/j.tet.2009.09.016
日期:2009.11
The TiCl4-mediated formal [3+3] cyclocondensation of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 1,1-dimethoxy-4,4-dichlorobut-1-en-3-one afforded a variety of functionalized 6-dichloromethyl-4-methoxysalicylates with very good regioselectivity. Some of the products were transformed into 6-formyl-4-methoxysalicylates. The employment of Me3SiOTf instead of TiCl4 resulted in a change of the regioselectivity
TiCl 4介导的1,3-双(三甲基甲硅烷氧基)-1,3-丁二烯与1,1-二甲氧基-4,4-二氯丁-1-烯-3-酮的正式[3 + 3]环缩合反应提供了多种具有非常好的区域选择性的官能化6-二氯甲基-4-甲氧基水杨酸酯。将一些产物转化为6-甲酰基-4-甲氧基水杨酸酯。使用Me 3 SiOTf代替TiCl 4会导致区域选择性的变化并形成功能化的2-(二氯甲基)吡喃-4-酮。