Generation of the trans-anti-trans A-B-C ring system of castasterone by intramolecular Diels-Alder reaction

Tetrahedron Letters

Volumn 40, Issue 34, 1999, Pages 6249-6252

  Zoller, T ^a   Uguen, D ^a  

^a UNIVERSITÉ DE STRASBOURG   (France)

Author keywords

[No Author keywords available]

Indexed keywords

CASTASTERONE; CYCLOHEXANE DERIVATIVE; KETONE DERIVATIVE; UNCLASSIFIED DRUG;

ARTICLE; CHEMICAL MODIFICATION; CHEMICAL REACTION; CYCLIZATION; HYDROGENATION; OXIDATION; REACTION ANALYSIS; STEREOCHEMISTRY;

BETULACEAE;

EID: 0033588065     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(99)01297-6     Document Type: Article

References (8)

1. Zoller, T.; Uguen, D.; De Cian, A.; Fischer, J.; Sablé, S. Tetrahedron Lett. 1997, 38, 3409-3412.
2. Zoller, T.; Uguen, D. Eur. J. Org. Chem. 1999, 1545-1550.
3. See following paper.
4. 3): 0.7 (t, J=4.5 Hz, 1H), 0.94 (s, 3H), 0.99-2.05 (m, 17H), 2.42 (dd, J=16, 3.5 Hz, 1H).
5. Previously (see ref. 1 and quoted reference therein), IMDA reaction of the E isomer of compound 2a has been shown to proceed via an endo-chair transition slate to give the cis-syn-trans isomer CST-3.
6. With the keto sulfones 3b and 3e, as well as with the keto ester 3c, the exo (vs endo) denomination is not obvious: should the sulfonyl and the methoxycarbonyl groups be more efficient than the ketone functionality with regards to the activation of the dienophilic system, the corresponding transition states will be more adequately designated as endo-chair. However, literature data dealing with the intermolecular Diels-Alder reaction of related β-sulfonyl- and β-alcoxycarbonyl-vinylketone strongly suggest that the dominant directional effect is developed by the ketone functionality (see, for instance: Leon, F. M.; Carretero, J. C. Tetrahedron Lett. 1991, 32, 5405-5408).
7. Parker, W. L.; Woodward, R. B. J. Org. Chem. 1969, 34, 3085-3089.
8. Aburatani, M.; Takeuchi, T.; Mori, K. Synthesis 1987, 181-183.