Direct Total Syntheses of Frenolicin B and Kalafungin via Highly Regioselective Diels-Alder Reactions
摘要:
Frenolicin B, an anticoccidial agent, has been synthesized in six steps from ketone 3. Racemic kalafungin, an antifungal agent, has been synthesized in five steps. The key step in both syntheses, a regioselective Diels-Alder reaction, proceeds with complete regiocontrol and in excellent yield. One rationale for the remarkable stereocontrol is that the lactone ring induces ring-puckering in the quinone subunit which, in consort with electrostatic repulsion, contributes to the regioselectivity.
Direct Total Syntheses of Frenolicin B and Kalafungin via Highly Regioselective Diels-Alder Reactions
摘要:
Frenolicin B, an anticoccidial agent, has been synthesized in six steps from ketone 3. Racemic kalafungin, an antifungal agent, has been synthesized in five steps. The key step in both syntheses, a regioselective Diels-Alder reaction, proceeds with complete regiocontrol and in excellent yield. One rationale for the remarkable stereocontrol is that the lactone ring induces ring-puckering in the quinone subunit which, in consort with electrostatic repulsion, contributes to the regioselectivity.
Radical Conjugate Addition of Aryl-Tethered β-Alkoxyacrylates: Formal Synthesis of (±)-Frenolicin B and (±)-epi-Frenolicin B
作者:Christopher Donner
DOI:10.1055/s-0029-1217118
日期:2010.2
The radical conjugate addition of aromatic-tethered O-stannyl ketyl radicals to β-alkoxyacrylates is demonstrated for the preparation of benzopyran-γ-lactone-fused tricyclic systems. This method is then applied to the stereodivergent formal synthesis of the kinase inhibitor (±)-frenolicin B and (±)-epi-frenolicin B.
芳香族束缚的 O-甲锡烷基自由基与 β-烷氧基丙烯酸酯的自由基共轭加成被证明可用于制备苯并吡喃-γ-内酯稠合三环系统。然后将该方法应用于激酶抑制剂 (±)-frenolicin B 和 (±)-epi-frenolicin B 的立体分歧形式合成。
Direct Total Syntheses of Frenolicin B and Kalafungin via Highly Regioselective Diels-Alder Reactions
作者:George A. Kraus、Jun Li、Mark S. Gordon、Jan H. Jensen
DOI:10.1021/jo00110a017
日期:1995.3
Frenolicin B, an anticoccidial agent, has been synthesized in six steps from ketone 3. Racemic kalafungin, an antifungal agent, has been synthesized in five steps. The key step in both syntheses, a regioselective Diels-Alder reaction, proceeds with complete regiocontrol and in excellent yield. One rationale for the remarkable stereocontrol is that the lactone ring induces ring-puckering in the quinone subunit which, in consort with electrostatic repulsion, contributes to the regioselectivity.