l-Proline catalyzed multicomponent reaction of 3,4-dihydro-(2H)-pyran, urea/thiourea, and aldehydes: diastereoselective synthesis of hexahydropyrano pyrimidinones (thiones)
作者:Jyoti Pandey、Namrata Anand、Rama P. Tripathi
DOI:10.1016/j.tet.2009.09.002
日期:2009.11
An organocatalytic multicomponent reaction involving 3,4-dihydro-(2H)-pyran, aromatic aldehydes, and urea/thiourea as substrates and l-proline/TFA as catalyst afforded hexahydropyrano pyrimidinones (thiones) in good yields. The method is simple, economical, and ecofriendly to generate hexahydropyrano pyrimidinones as precursors for many biologically active molecules and fused oxazines (PA-824), the