Mechanistic studies on the diastereoselectie halohydroxylation of γ-δ unsaturated carboxamides

Tetrahedron Letters

Volumn 37, Issue 38, 1996, Pages 6843-6846

  Rossen, K ^a   Reamer, R A ^a   Volante, R P ^a   Reider, P J ^a  

^a MERCK RESEARCH LABORATORIES   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ORGANOBROMINE DERIVATIVE; ORGANOIODINE DERIVATIVE;

ARTICLE; DRUG SYNTHESIS; HYDROXYLATION; REACTION ANALYSIS; STEREOCHEMISTRY;

EID: 0030590407     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/0040-4039(96)01529-8     Document Type: Article

References (18)

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2. (b) Maligres, P.E.; Weissman, S.A.; Upadhyay, V.; Cianciosi, S.J.; Reamer, R.A.; Purick, R.M.; Sager, J.; Rossen, K.; Eng, K.K.; Askin, D.; Volante, R.P.; Reider, P.J. Tetrahedron 1996, 52, 3327
3. 2. (a) Vacca, J.P.; Dorsey, B.D.; Schleif, W.A.; Levin, R.B.; McDaniel, S.L.; Darke, P.L.; Zugay, J.; Quintero, J.C.; Blahy, O.M.; Sardana, V.V.; Schlabach, A.J.; Graham, P.I.; Condra, J.H.; Gotlib, L.; Holloway, M.K.; Lin, J.; Chen, I.-W.; Vastag, K.; Ostovic, D.; Anderson, P.S.; Emini, E.A.; Huff, J.R. Proc. Natl. Acad. Sci. USA 1994, 91, 4096;
4. (b) Idem., J. Med. Chem. 1994,37, 3443.
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6. 4. Askin, D.; Eng, K.K.; Rossen, K.; Purick, R.M.; Wells, K.M.; Volante, R.P.; Reider, P.J. Tetrahedron Lett. 1994, 35, 673.
7. 5. Tamaru, Y.; Mizutani, M.; Furukawa, Y.; Kawamura, S.; Yoshida, Z.; Yanagi, K.; Minobe, M. J. Am. Chem. Soc. 1984, 106, 1079-1085.
8. 6. R.W. Hoffmann Angew. Chem. Int. Ed. Engl. 1992, 31, 1124.
9. 7. Downs, A.J.; Adams, C.J., in Comprehensive Inorganic Chemistry, ed. Trotman-Dickenson, A.F., Pergamon, New York, 1973, vol.2, p. 1107.
10. 18O).
11. 9. The following scheme was used to prepare 9: (matrix presented)
12. 10. Proton spin-spin coupling constants and NOE difference experiments were used to assign the epoxide methylene protons in protio 11. Comparison with mono-deutero 11 permits the stereochemical assignments as shown.
13. 11. The following scheme was used to prepare 13b: (matrix presented)
14. 6, 100.5 MHz) δ 178.2, 141.5, 136.5, 136.3, 129.2, 129.0, 128.8, 127.2, 125.9, 125.3, 103.0, 89.8, 82.1, 70.2, 46.6, 37.0, 35.3, 31.6, 31.5, 25.7, 24.1. The regiochemistry of the imidate and the relative stereochemistry in the five-membered ring were determined using NOE difference spectroscopy. (b) Epimerization (ca. 50%) of the iodomethyl sidechain was observed in the analogous preparation of the iodo compound 12a. Competitive displacement of the triflate by the neighboring iodine and opening of the resulting iodonium ion 19 by the amide carbonyl led to an epimerized iodomethyl group in 20: (matrix presented)
15. 3, 100.5 MHz) δ 161.8, 142.4, 140.4, 136.5, 130.7, 128.0, 127.7, 126.8, 126.4, 125.7, 124.5, 100.5, 76.5, 73.3, 62.2, 48.8, 47.4, 46.8, 44.7, 37.2, 25.5, 24.7, 6.9. The relative stereochemistry of the five-membered ring was determined using NOE difference spectroscopy.
16. (b) Kitagawa, O.; Hanano, T.; Hirata, T.; Inoue, T.; Taguchi, T. Tetrahedron Lett. 1992, 33, 1299.
17. 14. (a) Deslongchamps, P. Stereoelectronic Effects in Organic Chemistry; Pergamon: Oxford, England, 1983.
18. (b) Sinnot, M.L. Adv. Phys. Org. Chem. 1988, 24, 113.