A regiocontrolled intermolecular Diels−Alder reaction of an o-benzoquinone followed by an intramolecular nitrile oxide cyclization is employed to prepare the BCD fragment of viridin. The AE segment is attached to it by means of an intramolecular Diels−Alder reaction of an o-benzoquinone monoketal generated in situ from tricycle 15 and 5-trimethylsilyl-2E,4E-pentadienol 20. The silyl substituent at
邻苯甲醌的区域控制的分子间狄尔斯-阿尔德反应,然后分子内的
一氧化氮环化被用来制备viridin的BCD片段。AE段通过三轮车15和5-trimethylsilyl-2 E,4 E- pentadienol 20原位生成的邻苯二醌单
缩酮的分子内Diels-Alder反应与之连接。五环产物的C-1处的甲
硅烷基取代基指导C 2 -C 3的二羟基化与其β面形成双键。描述了在环A中1α-三甲基甲
硅烷基-2β,3β-二羟基五环到具有氧取代基的其他几种的各种转化。这些产物40之一在环A,B和E中具有与
天然产物渥曼诺酮3相同的结构和相对立体
化学。