Practical synthesis of C1–8 fragment of autolytimycin via a chelation-controlled diastereoselective addition of diisopropenylzinc to α-methoxy aldehyde
作者:Fan Yang、Liang Feng、Nengzhong Wang、Xuge Liu、Jun Li、Yuehai Shen
DOI:10.1016/j.tet.2013.08.067
日期:2013.11
capable of delivering 41% overall yield at multi-gram scale. As a key step, a chelation-controlled isopropenylation of α-oxygenated aldehydes was established with a reagent combination of diisopropenylzinc, magnesium halide, and a dichloromethane/toluene mixed solvent. Cram-chelate isopropenylation products dominated for aldehydes with a small α-substituents, such as –OMe and –OBn groups, while the Felkin
自身霉素的C1–8片段是通过可靠的10步路线合成的,该路线能够以克为单位提供41%的总收率。作为关键步骤,使用二异丙烯基锌,卤化镁和二氯甲烷/甲苯混合溶剂的试剂组合建立了α-氧化醛的螯合控制的异丙烯基化。蛤-螯合物异丙烯基化产物主要被具有少量α-取代基的醛所占据,例如–OMe和–OBn基团,而Felkin产物可以通过庞大的–OTBS基团获得。