The tricyclic ester 1 was transformed by a sequence of intramolecular Michael and alkylation reactions into the pentacyclic lactone 10 from which the (+)-15-desoxy derivatives of longikaurin C 2 and effusin 4 were then prepared.
Synthetic studies on Rabdosia diterpene lactones I: The preparation of a key tricyclic intermediate
β Scribed by Martin J. Kenny; Lewis N. Mander; S.Paul Sethi
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- French
- Weight
- 230 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0040-4039
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β¦ Synopsis
A strategy is proposed for the synthesis of Rabdosia diterpene lactones, eg. effusin 2 and the preparation of a suitable tricyclic intermedia= 6 described.
π SIMILAR VOLUMES
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
In the course of the cited synthesis of (\*)-la, compound 3a was in fact obtained as a major epimer, along with 3b. The synthesis of (&)-la was then carried on with the minor epimer 3b [4].