decahydrofluorene skeleton of GKK1032s. The C-ring was constructed by intramolecular cyclization reaction between a chiral epoxide and silyl enol ether, and the dienophile moiety was introduced concurrently. In addition, the AB-rings were stereoselectively constructed using novel sequential retro Diels–Alder (DA) and intramolecular Diels–Alder (IMDA) reactions. Several further modifications of the IMDA adduct were
GKK1032s,其从青霉属sp。的培养液中分离。GKK1032,表现出抗肿瘤活性。我们构建了GKK1032的完全精心设计的十氢
芴骨架。通过手性
环氧化物和甲
硅烷基烯醇醚之间的分子内环化反应构建C环,并同时引入亲二烯体部分。此外,AB环是使用新型顺序逆向Diels-Alder(
DA)和分子内Diels-Alder(I
MDA)反应立体选择性地构建的。对I
MDA加合物进行了数种进一步的修饰,导致所需的羟基酯(包括9个立体中心)的不对称合成。