Asymmetric hetero-Diels–Alder reactions of alkenyldihydrooxazoles. Synthesis of oxazolo[3,2-c]pyrimidines and related compounds
作者:Mark C. Elliott、Elbertus Kruiswijk
DOI:10.1039/a905700e
日期:——
Alkenyldihydrooxazoles undergo a highly diastereoselective formal aza-Diels–Alder reaction with aryl and arenesulfonyl isocyanates to give oxazolo[3,2-c]pyrimidines. Depending on the substitution pattern of the alkenyldihydrooxazole, these compounds may then undergo addition of a second equivalent of the isocyanate to give either tetrahydrooxazolo[3,2-c]pyrimidine-8-carboxamides or octahydroazeto[2
烯基二氢恶唑与芳基和芳烃磺酰基异氰酸酯进行高度非对映选择性的正式aza-Diels-Alder反应,生成oxazolo [3,2- c ]嘧啶。然后,根据烯基二氢恶唑的取代方式,可以将这些化合物加入第二当量的异氰酸酯,以得到四氢恶唑并[ 3,2 - c ]嘧啶-8-羧酰胺或八氢氮杂并[2,3- d ]恶唑[3]。 ,2- c ]嘧啶。第二种添加对空间和电子因素敏感,在某些情况下可以防止。