Intramolecular Diels-Alder and Cope reactions of o-quinonoid monoketals and their adducts: Efficient syntheses of (±)-xestoquinone and heterocycles related to viridin

Journal of Organic Chemistry

Volumn 62, Issue 8, 1997, Pages 2330-2331

  Carlini, Rina ^a   Higgs, Kerianne ^a   Older, Christina ^a   Randhawa, Sab ^a   Rodrigo, Russell ^b  

^a UNIVERSITY OF WATERLOO   (Canada)

^b WILFRID LAURIER UNIVERSITY   (Canada)

Author keywords

[No Author keywords available]

Indexed keywords

ANTIFUNGAL AGENT; FURAN DERIVATIVE; NAPHTHO[1,8 BC]FURAN DERIVATIVE; UNCLASSIFIED DRUG; VIRIDIN; XESTOQUINONE;

ARTICLE; DRUG SYNTHESIS; IN VITRO STUDY; REACTION ANALYSIS;

EID: 0030962373     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo970394l     Document Type: Article

References (15)

1. For a recent review see: Hanson, J. R. Nat. Prod. Rep. 1995, 12, 381-4.
2. (a) Maddaford, S. P.; Anderson, N. G.; Cristofoli, W. A.; Keay, B. A. J. Am. Chem. Soc. 1996, 118, 10766-73 and references therein.
3. (b) Harada, N.; Sugioka, T.; Uda, H.; Kuriki, T.; Kobayashi, M.; Kitagawa, I. J. Org. Chem. 1994, 59, 6606-13.
4. Kanematsu, K.; Soejima, S.; Wang, G. Tetrahedron Lett. 1991, 32, 4761-4.
5. Burns, P. A.; Taylor, N. J.; Rodrigo, R. Can. J. Chem. 1994, 72, 42-50.
6. (a) Yamamura, S.; Shizuri, Y.; Shigemori, H.; Okuno, Y.; Okhubo, M. Tetrahedron 1991, 47, 635-644.
7. (b) Chu, C.-S.; Lee, T.-H.; Liao, C.-C. Synlett 1994, 635-6.
8. All the IMDA reactions were face selective and endo with respect to the o-quinonoid ring.
9. A 1,3-cyclohexadiene-5,6-diol carrying a pendant diene unit at the C-5 hydroxyl group produced only the bridged adduct in the IMDA reaction: Hudlicky, T.; Boros, C. H.; Boros, E. E. Synthesis 1992, 174-6. We thank a reviewer for bringing this to our attention.
10. 13C NMR correlations made with the tricyclic moieties of the other adducts. An important diagnostic feature emerged when a small W-coupling of 2.2 Hz between H-1β and H-10c (established by decoupling and 2D correlation) was observed in the endo-isomer of 10a. This coupling is found in every other endo isomer of the tricyclic unit but is absent in every exo isomer.
11. It has been observed in our laboratory and in others that intermolecular Diels-Alder reactions of o-benzoquinones produce only the endo-adducts: Carlini, R.; Fang, C.-L.; Herrington, D.; Higgs, K.; Rodrigo, R.; Taylor, N. Aust. J. Chem. 1997, in press.
12. Rodrigo, R. Tetrahedron 1988, 44, 2093-2135 and references therein.
13. An X-ray crystal structure of 17 established its relative stereo-chemistry. An adduct resulting from reaction of the isobenzofuran at the C2-C3 bond was also isolated (8%). See: Sadeghy, B. M. M.; Rickborn, B. J. Org. Chem. 1983, 48, 2237-46.
14. All compounds were characterized by NMR and other common spectroscopic methods. Full details for the preparation of all previously unknown compounds will be published later.
15. Hydrocortisone has recently been converted to wortmannin: Sata, S.; Nakada, M.; Shibasaki, M. Tetrahedron Lett. 1996, 37, 6141-44.