The Total Synthesis of (±)-Ginkgolide B
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- 作者：Michael T. Crimmins ; Jennifer M. Pace ; Philippe G. Nantermet ; Agnes S. Kim-Meade ; James B. Thomas ; Scott H. Watterson ; and Allan S. Wagman
- 刊名：Journal of the American Chemical Society
- 出版年：2000
- 出版时间：September 6, 2000
- 年：2000
- 卷：122
- 期：35
- 页码：8453 - 8463
- 全文大小：471K
- 年卷期：v.122,no.35(September 6, 2000)
- ISSN：1520-5126
文摘
The total synthesis of the potent PAF antagonist ginkgolide B has been accomplished. The complexarchitecture of ginkgolide B which includes six rings, eleven stereogenic centers, ten oxygenated carbons, andfour contiguous fully substituted carbons is a daunting challenge for chemical synthesis. The synthesis ofginkgolide B was accomplished through a stereoselective intramolecular photocycloaddition of enone 5 toconstruct the congested core of the molecule. The photocycloaddition substrate was prepared through technologyfor the construction of carboalkoxycyclopentenones previously reported from these laboratories. Regioselectivecyclobutane fragmentation and further functionalization of the photoadduct 4 provided the key pentacyclicintermediate. Acid-catalyzed rearrangement and epoxide opening were key transformations in the productionof ginkgolide B from the pentacyclic intermediate.