Diastereoselective Synthesis of 2,4-Disubstituted Tetrahydropyranols and Ethers via a Prins-Type Cyclization Catalyzed by Scandium Triflate
作者:Wen-Chun Zhang、Chao-Jun Li
DOI:10.1016/s0040-4020(00)00152-6
日期:2000.4
The reaction of aldehydes with homoallylic alcohols catalyzed by scandium triflate gives rise to the formation of 2-substituted tetrahydropyran-4-ols and ethers in good overall yields and with ‘all-cis’ configurations and high diastereoselectivities. The stereochemistries of these products were assigned with the assistance of coupling constants and NOE. Factors affecting the reaction have been examined
醛与三氟甲磺酸scan催化的均丙醇反应生成了2-取代的四氢吡喃-4-醇和醚,总收率高,具有“顺式”构型和高非对映选择性。这些产物的立体化学在偶合常数和NOE的帮助下进行分配。已经详细研究了影响反应的因素。发现该反应在氯仿中最有效。各种芳香族和脂肪族醛均顺利进行环化。已经提出了用于该反应的催化循环。