Total synthesis of dl-coccuvinine 1a and dl-coccolinine 2a, "abnormal-type" erythrinan alkaloids lacking the C(16) O-function at the aromatic ring, was effectively achieved by using the Diels–Alder reaction of dioxopyrroline. Isoquinolinopyrrolinedione 6a, a key dienophile, was synthesized via the tetrahydroisoquinoline 5a, which was prepared by Bischler–Napieralski cyclization of the amide 4a at the unactivated position. The Diels–Alder adduct 7a of 1,3-bis(trimethylsilyloxy)-butadiene with 6a with converted stereoselectively into these alkaloids in short steps.
通过使用二氧杂环戊二烯的Diels-Alder反应,成功地合成了缺乏芳香环上C(16) O功能的“异常型”赤露花生物碱dl-coccuvinine 1a和dl-coccolinine 2a。通过四氢异喹啉 5a 合成了关键的双亚烯体异喹啉吡咯二酮 6a,该化合物是通过在未活化位置的酰胺 4a 上进行 Bischler-Napieralski 环化得到的。1,3-双(三甲基硅氧基)-丁二烯与 6a 的 Diels-Alder 加合物 7a 在短步骤中立体选择性地转化为这些生物碱。