Efficient synthesis of (2S,3S)-2-ethyl-3-methylvaleramide using (1S,2S)-pseudoephedrine as a chiral auxiliary

Organic Process Research and Development

Volumn 13, Issue 3, 2009, Pages 463-467

  Li, Bin Feng ^a   Hughes, Robert M ^a   Le, Jackie ^a   McGee, Kevin ^a   Gallagher, Donald J ^a   Gross, Raymond S ^a   Provencal, David ^a   Reddy, Jayachandra P ^a   Wang, Peng ^a   Zegelman, Lev ^a   Zhao, Yuxin ^a   Zook, Scott E ^a  

^a NEUROCRINE BIOSCIENCES INC   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 66249130038     PISSN: 10836160     EISSN: 1520586X     Source Type: Journal    
DOI: 10.1021/op800260j     Document Type: Article

References (12)

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3. Farina, V.; Reeves, J. T.; Senanayake, C. H.; Song, J. J. Chem. Rev. 2006, 106, 2734-2793.
4. (a) Roeder, M.; Spiegelstein, O.; Schurig, V.; Bialer, M.; Yagen, B. Tetrahedron: Asymmetry 1999, 10, 841.
5. Bialer, M.; Yagen, B.; Spiegelstein, O.; Roeder, M.; Schurig, V. PCT Int. Appl. 9830536, 1998.
6. It should be noted that careful handling of compound 6 is required due to the stench associated with it. (3S)-Methylvaleric acid 6 is also commercially available from AstaTech Inc. and other companies.
7. (a) Myers, A. G.; Yang, B. H.; Chen, H.; McKinstry, L.; Kopecky, D. J.; Gleason, J. L. J. Am. Chem. Soc. 1997, 119, 6496.
8. Myers, A. G.; Yang, B. H.; Chen, H.; Gleason, J. L. J. Am. Chem. Soc. 1994, 116, 9361.
9. Reyes, E.; Vicario, J. L.; Carrillo, L.; Badia, D.; Uria, U.; Iza, A. J. Org. Chem. 2006, 71, 7763.
10. Efforts to efficiently form and convert 8b directly to 1 were unsuccessful.
11. A small-scale experiment showed that the pseudoephedrine auxiliary can be recovered from the hydrolysis mixture in ∼75% yield by NaOH basification and CH2Cl2 extractive workup.
12. Levin, D. Org. Process Res. Dev. 1997, 1, 182.