An enantioselective route for the total synthesis of forskolin, a potent activator of adenylate cyclase, has been developed which is based on reduction of dienone 3 to the (S)-alcohol4 and conversion in two steps to tricyclic lactone 9, obtained in optically pure form simply by recrystallization. A
A short and efficient enantioselective route to a key intermediate for the total synthesis of forskolin
β Scribed by E.J Corey; Paul Da Silva Jardine
- Publisher
- Elsevier Science
- Year
- 1989
- Tongue
- French
- Weight
- 285 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0040-4039
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β¦ Synopsis
A simple route for the enanrioselective synthesis of key intermediates (11 and 12) for the total synthesis of forskolin has been developed starting from acid 6 and (S)-alcohol 5. The latter is prepared by enantioselective catalytic CBS reduction of dienone 3, and is converted by an intramolecular Diels-Alder reaction to tricyclic lacrone 9.
π SIMILAR VOLUMES
The Ziegler intermediate 2, previously used in three total syntheses of forskolin (1) has been synthesized efficiently from enone 3. The key transformation of this sequence is the early and stereoselective introduction of the C-6, C-7 oxygen functional groups present in the natural product. The hig
The iodo lactone I, which has been used as a key intermediate for the synthesis of the six natural primary prostaglandins, is readily available by a synthetic process in which the average yield per step is 95% (l-4). Although the A prostaglandins can be derived from the primary E prostaglandins by d
Preparation of the "Ziegler key intermediate" 2from lactone 3, readily obtained from hydroxy-O-ionone, was studied. In a first exploratory approach, lactones 11 and 13 were obtained but further transformations aimed at setting the ring junction were unsuccessful due to unexpected rearrangements. Thr