Diastereoselective alkylations of β-tetrazolyl propionic acids

Tetrahedron Letters

Volumn 45, Issue 1, 2004, Pages 111-112

  Yang, Michael G ^a   Modi, Dilip P ^a   Wexler, Ruth R ^a   Olson, Richard E ^a  

^a BRISTOL MYERS SQUIBB   (United States)

Author keywords

Alkylation; Chelation biol; Diastereoselectivity; Tetrazole

Indexed keywords

PROPIONIC ACID DERIVATIVE;

ALKYLATION; ARTICLE; CHELATION; MOLECULAR MECHANICS; MOLECULAR MODEL; STEREOCHEMISTRY;

EID: 0742304467     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2003.10.118     Document Type: Article

References (18)

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9. Other related reaction conditions were also examined. However, the results were less than satisfactory, see: Thomas E.W. Synthesis. 1993;767.
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12. 4, filtered, and concentrated in vacuo to give clean product 5a in 92% yield.
13. It is worth mentioning that both LiHMDS and NaHMDS were also examined as potential bases to enolizing acid 4 . However, in both cases, the reactions failed to provide any desired products and only gave the starting material.
14. Although the minor anti-diastereoisomer was not sufficient to be isolated, its existence was confirmed by LC/MS spectrometer. Given the result of excellent diastereoselectivity, we decided not to change the solvent or to add any chelate additives to affect the reaction diastereoselectivity.
15. For related seven-membered ring transition states involving succinate enolates see: Beckett R.P., Crimmin M.J., Davis M.H., Spavold Z. Synlett. 1993;137.
16. Flippin L.A. Tetrahedron Lett. 32:1991;6857.
17. 1H NMR spectra of compound 5b and the saponification product 3b . Compound 3b was synthesized from intermediate 1d as illustrated in Eq. 2. For both stereocenters in 1d , the absolute stereoconfiguration is known.
18. For entries 4-9, some of the unreacted starting materials were recovered during the purification process.