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。