Application of reactive enols in synthesis: A versatile, efficient, and stereoselective construction of the welwitindolinone carbon skeleton [11]

Journal of the American Chemical Society

Volumn 121, Issue 26, 1999, Pages 6326-6327

  Wood, John L ^a   Holubec, Alexandra A ^a   Stoltz, Brian M ^a   Weiss, Matthew M ^a   Dixon, Julie A ^a   Doan, Brian D ^a   Shamji, Mohammed F ^a   Chen, Jennifer M ^a   Heffron, Timothy P ^a  

^a YALE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ALKALOID; INDOLE DERIVATIVE; UNCLASSIFIED DRUG; WELWITINDOLINONE;

CYANOBACTERIUM; LETTER; MOLECULAR INTERACTION; STEREOCHEMISTRY; STRUCTURE ANALYSIS; SYNTHESIS;

EID: 0033532924     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja991022s     Document Type: Letter

References (17)

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3. (c) Smith, C. D.; Zilfou, J. T.; Stratmann, K.; Patterson, G. M. L.; Moore, R. E. Mol. Pharm. 1995, 47, 241.
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7. This sequence is very amenable to large scale and has been used to produce several kilos of 9.
8. For leading references relevant to the C-H insertion chemistry of 5, see: (a) Ye, T.; McKervey, M. A. Chem. Rev. 1994, 94, 1091. (b) Wenkert, E.; Liu, S. Synthesis 1992, 323. (c) Taber, D. F.; Petty, E. H. J. Org. Chem. 1982, 47, 4808.
9. For leading references relevant to the C-H insertion chemistry of 5, see: (a) Ye, T.; McKervey, M. A. Chem. Rev. 1994, 94, 1091. (b) Wenkert, E.; Liu, S. Synthesis 1992, 323. (c) Taber, D. F.; Petty, E. H. J. Org. Chem. 1982, 47, 4808.
10. For leading references relevant to the C-H insertion chemistry of 5, see: (a) Ye, T.; McKervey, M. A. Chem. Rev. 1994, 94, 1091. (b) Wenkert, E.; Liu, S. Synthesis 1992, 323. (c) Taber, D. F.; Petty, E. H. J. Org. Chem. 1982, 47, 4808.
11. We have found that Montmorillonite K10 also suppresses the formation of cycloheptatrienes in the aryl C-H insertions of α-diazo esters. These results will be published elsewhere.
12. Wood, J. L.; Moniz, G. A.; Pflum, D. A.; Stoltz, B. M.; Holubec, A. A.; Dietrich, H-. J. J. Am. Chem. Soc. 1999, 121, 1748.
13. Trapping studies have confirmed the intermediacy of enols in the current study, see Supporting Information for details.
14. Ziegler, F. E. Chem Rev. 1988, 88, 1423 and references therein.
15. This propensity for rearrangement is also observed for compound 21 but can be suppressed by in situ trapping of either 19 or 21 as the corresponding trifluoroacetate, see Supporting Information for details. Attempts to trap 24 and 25 in a similar fashion failed.
16. Similar experiments initiated with vinyl Grignard reagents were found to proceed with poor stereoselectivity.
17. Although ring-closing metathesis has been widely used in synthesis, its application in constructing medium-sized bridged carbocycles is less common. For a recent discussion, see: Morehead, A., Jr.; Grubbs, R. Chem. Commun. 1998, 275.