M. Mikołajczyk et al. / Tetrahedron: Asymmetry 20 (2009) 1948–1951
1951
4.5. Kinetic resolution of racemic dithiophosphate 5 by
oxidation with CPO/H2O2 system
suspension was stirred for 20 h and after filtration of the solid
material, the filtrate containing product was separated by column
chromatography to give pure oxon (+)-(R)-4 [a]D = +26.9 (c 0.55,
To a magnetically stirred ( )-5 (20 mg, 0.074 mmol) and CPO
(300 U) in a mixture of citrate buffer, pH5 (19 mL), and EtOH
(1 mL), H2O2 (0.082 mmol) in 1 mL of buffer was added in portions.
The reaction was monitored by HPLC. After 22 days, the reaction
was quenched with sodium sulfite. The aqueous layer was ex-
tracted with CHCl3 and the organic extract dried over MgSO4. After
removal of the solvent, the crude material (15 mg, 77% yield) was
separated by chromatography (SiO2, 230–400 mesh, CHCl3) to give
MeOH), (11 mg, 43% yield).
Acknowledgment
Financial support by the Polish Ministry of Science and Higher
Education, Grant No. PBZ- KBN- 126/T09/03, is gratefully acknow-
ledged.
unreacted (+)-(R)-5 (5 mg); [
a]D = +24.0 (c 0.25, CHCl3), 97% ee
Reference
[Chiralpak AS; hexane–(iso-PrOH–EtOH–THF, 3:1:1) 9:1; fl 0.7
1. Fest, C.; Schmidt, K.-J. The Chemistry of Organophosphorus Pesticides; Springer:
Berlin, Heidelberg, New York, 1973.
2. Eto, M. Organophosphorus Pesticides: Organic and Biological Chemistry; CRC:
Cleveland, OH, 1974.
mL/min, RT = 11.10 min] and oxon (À)-(S)-4 (5 mg); [ D = À29.6
a
]
(c 0.25, MeOH), 99.6% ee [Chiralpak AS; hexane–(iso-PrOH–EtOH–
THF, 3:1:1) 9:1; fl 0.7 mL/min, RT = 28.88 min].
3. Hirashima, A.; Eto, M. Agric. Biol. Chem. 1983, 47, 2831–2839.
4. Seiber, J. N.; Tolkmith, H. Tetrahedron 1969, 25, 381–387.
5. (a) Kurihara, N.; Miyamoto, J.; Paulson, G. D.; Zeeh, B.; Skidmore, M. W.;
Hollingworth, R. M.; Kuiper, H. A. Pure Appl. Chem. 1997, 69, 1335–1348; (b)
Williams, A. Pest. Sci. 1996, 46, 3–9.
4.6. Oxidation of (À)-(S)-dithiophosphate 5 with CPO/H2O2
system
6. Kiełbasin´ ski, P.; Mikołajczyk, M. Chiral Heteroatom-containing Compounds.
In Future Directions in Biocatalysis; Matsuda, T., Ed.; Elsevier, 2007; pp
159–203.
7. (a) Lewis, V. E.; Donarski, W. J.; Wild, J. R.; Raushel, F. M. Biochemistry 1988, 27,
1591–1597; (b) Wu, F.; Li, W. S.; Chen-Goodspeed, M.; Sogorb, M. A.; Raushel,
F. M. J. Am. Chem. Soc. 2000, 122, 10206–10207; (c) Li, W.-S.; Li, Y.; Hill, C. M.;
Lum, K. T.; Raushel, F. M. J. Am. Chem. Soc. 2002, 124, 3498–3499.
8. Huang, L.-F.; Su, B.; Jao, S.-Ch.; Liu, K.-T.; Li, W.-S. ChemBioChem 2006, 7, 506–
514.
9. Quinn, D. M. Chem. Rev. 1987, 87, 955–979.
10. Thompson, C. M.; Frick, J. A.; Natke, C. M.; Hansen, L. K. Chem. Res. Toxicol. 1989,
2, 386–391.
11. Ryu, S.; Lin, J.; Thompson, C. M. Chem. Res. Toxicol. 1991, 4, 517–520.
12. Hernandez, J.; Robledo, N. R.; Velasco, L.; Quintero, R.; Pickard, M. A.; Vasquez-
Duhalt, R. Pestic. Biochem. Physiol. 1998, 61, 87–94.
To
a
magnetically stirred solution of (À)-(S)-5 (20 mg,
D = À23.2 (CHCl3), 93.1% ee) and CPO (300 U) in a
0.074 mmol, [
a
]
mixture of citrate buffer, pH 5 (10 mL), and acetonitrile (10 mL),
hydrogen peroxide (0.1 mmol in 1 mL of buffer, pH 5) was added.
Stirring was continued at room temperature for ca one month.
Products were extracted with CH2Cl2. The solution was concen-
trated under reduced pressure and the residue was separated by
column chromatography (SiO2, 230–400 mesh, CH2Cl2) to give
unreacted (+)-(R)-5 (0.87 mg, 4.7%, 76% ee) and (À)-(S)-4 (10 mg,
51.3%), [
a
]
D = À29.6 (CHCl3), 98.5% ee).
Oxidation of (+)-(R)-5, [
a]D = +23.1 (CHCl3, 98.8% ee) under the
13. Hilgetag, G.; Lehmann, G. J. Prakt. Chem. 1959, 8, 224–228.
14. Ryn, S.; Jackson, J. A.; Thompson, C. M. J. Org. Chem. 1991, 56, 4999–5002.
15. Omelan´ czuk, J.; Mikołajczyk, M. Tetrahedron 1971, 27, 5587–5591.
16. Maryanoff, B. E.; Tang, R. E.; Mislow, K. J. Chem. Soc., Chem. Commun. 1973, 273–
274.
above conditions led to the recovery of this unchanged enantiomer.
4.7. Oxidation of dithiophosphate (+)-(R)-5 with iodoxybenzene
17. Zhou, H.-J.; Hang, Y.-Q.; Li, Y.-G.; Wang, J. L.; Liu, X.-L.; Miao, F.-M.; Yang, S.-Ch.;
Jiang, X.-Ch.; Feng, R.; Yan, Z.-X. Phosphorus, Sulfur, Silicon 1995, 102, 185–193.
18. Mielniczak, G.; Łopusin´ ski, A. Synlett 2007, 505–508.
19. Fukuto, T. R. Pure Appl. Chem. 1978, 50, 1015–1032.
To dithioester 5, [a]D = +25.0 (c 1.35, CHCl3), (27 mg, 0.097
mmol) in CHCl3 (3 mL) iodoxybenzene (24 mg, 0.1 mmol) and a
few mg of K10-montmorillonite as an activator were added. The