Selective racemisation of esters: Relevance to enzymatic hydrolysis reactions

Tetrahedron Letters

Volumn 40, Issue 4, 1999, Pages 749-752

  Dinh, Phi M ^a   Williams, Jonathan M J ^a   Harris, William ^b  

^a University of Bath   (United Kingdom)

^b ROCHE PRODUCTS LTD   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ESTER DERIVATIVE;

ARTICLE; CATALYSIS; HYDROLYSIS; REACTION ANALYSIS; STEREOCHEMISTRY; SYNTHESIS;

EID: 0033593289     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(98)02362-4     Document Type: Article

References (13)

1. Ebbers, E. J.; Ariaans, G. J. A.; Houbiers, P. M.; Bruggnink, A; Zwanenburg, B., Tetrahedron 1997, 53, 9417-9476; Koh, J. H.; Jeong, H. M.; Park, J., Tetrahedron Lett. 1998, 39, 5545-5548.
2. Ebbers, E. J.; Ariaans, G. J. A.; Houbiers, P. M.; Bruggnink, A; Zwanenburg, B., Tetrahedron 1997, 53, 9417-9476; Koh, J. H.; Jeong, H. M.; Park, J., Tetrahedron Lett. 1998, 39, 5545-5548.
3. For a review on dynamic resolution, see: Caddick, S.; Jenkins, K., Chem. Soc. Rev., 1996, 447-456.
4. 2H), 1ml/min, 11.2 min (R) and 12.6 min (S), ester 2 using Chiralcel OJ column (90:10 hexane:iPrOH), 1ml/min, 9.6 min (R) and 7.8 min (S) and ester 3 using Chiralpak AD column (95:5 hexane:iPrOH) 1ml/min, 6.4 min (S) and 5.8 min (R).
5. DABCO also racemises the corresponding vinyl ester (the ee falls to 12.5% ee after 24h in acetonitrile at 40 °C). Both the phenyl ester 3 and the corresponding nitrophenyl ester undergo slow racemisation with triethylamine or trioctylamine (60-70% ee after 24h)
6. Phenyl ester 3 could be racemised by itself in the presence of sub-stoichiometric quantities of DABCO (0.2 equivalents in DMSO at 40 °C for 24 h reduced the ee to 28%)
7. Parmar, V. S.; Singh, A.; Bisht, K. S.; Kumar, N.; Belokon, Y. N.; Kochetkov, K. A.; Ikonnikov, N. S.; Orlava, S. A.; Tararov, V. I.; Saveleva, T. F., J. Org. Chem. 1996, 61, 1223-1227.
8. Um, P-J.; Drueckhammer, D. G., J. Am. Chem. Soc. 1998, 120, 5605-5610
9. Fülling, G.; Sih, J. C., J. Am. Chem. Soc. 1987, 109, 2845-2846.
10. Gu, Q-M.; Chen, C-S.; Sih, C. J., Tetrahedron Lett., 1986, 27, 1763-1766. HLE (Hog Liver Esterase) also gave good kinetic resolution results
11. 10 This research group has previously reported successful enzyme-catalysed dynamic resolution reactions for other substrates. Dinh, P.M.; Howarth, J. A.; Hudnott, A. R.; Harris, W.; Williams, J. M. J., Tetrahedron Lett., 1996, 37, 7623-7626. Allen, J. V.; Williams, J. M. J. Tetrahedron Lett., 1996, 37, 1859-1862
12. This research group has previously reported successful enzyme-catalysed dynamic resolution reactions forother substrates. Dinh, P.M.; Howarth, J. A.; Hudnott, A. R.; Harris, W.; Williams, J. M. J., Tetrahedron Lett., 1996, 37, 7623-7626. Allen, J. V.; Williams, J. M. J. Tetrahedron Lett., 1996, 37, 1859-1862
13. CLEC enzymes were purchased from Altus Biologics Inc. 40 Allston St. Cambridge, MA 02139-4211, USA..