D. Wiktelius et al. / Tetrahedron: Asymmetry 17 (2006) 2088–2100
2099
123, 8515–8519; (c) Ghosh, A. K.; Kim, J. H. Tetrahedron
Lett. 2003, 44, 7659–7661.
3. Kazlauskas, R. J.; Bornscheuer, U. T. In Biotechnology: A
Multi-Volume Comprehensive Treatise/Biotransformations I;
2nd ed.; Kelly, D. R., Ed.; Wiley-VCH: Weinheim, 1998; Vol.
8a, pp 37–192.
4. Wiktelius, D. Synlett 2005, 2113–2114, and references cited
therein.
5. (a) Yadav, J. S.; Nanda, S. Tetrahedron: Asymmetry 2001, 12,
3223–3234; (b) Toyooka, N.; Nemoto, H.; Kawasaki, M.;
Garraffo, H. M.; Spande, T. F.; Daly, J. W. Tetrahedron
2005, 61, 1187–1198.
Isocyanate (S)-10b (19 mg, 0.10 mmol) was dissolved in
t-BuOH (2 mL) in a screw-cap tube and the mixture heated
to 100 ꢁC for 14 h. The reaction was allowed to cool after
which DCM (10 mL) and H2O (5 mL) were added and
the phases were separated. The organic phase was dried
over MgSO4, filtered, and evaporated. Gradient flash chro-
matography on a short column (EtOAc/hexanes 1:20–1:4)
afforded the title compound (10 mg, 37%). The procedure
20
was repeated to prepare 36 mg of (S)-11b. ½aꢁD ¼ ꢀ28 (c
1.0, CHCl3);1H NMR d 4.45 (d, J = 8.4, 1H, NH), 4.04–
4.00 (m, 2H, H-1), 4.00–3.89 (m, 1H, H-2), 2.06 (s, 3H,
Ac), 1.71–1.60 (m, 1H, H-4), 1.43 (s, 9H, t-Bu), 1.32–1.21
(m, 2H, H-3), 0.92 (d, J = 2.6, 3H, Mea), 0.91 (d, J = 2.2,
3H, Meb); 13C NMR d 171.0 (CH3COO), 155.4 (NHCOO),
79.3 (qC), 66.8 (C-1), 47.7 (C-2), 40.9 (C-3), 28.3 (3C, t-Bu),
24.7 (Mea), 23.0 (C-4), 22.2 (Meb), 20.8 (Ac); IR m = 2959,
1745, 1716, 1524, 1519, 1367, 1239, 1171 cmꢀ1. Anal. Calcd
for C13H25NO4: C 60.21, H 9.72, N 5.40. Found: C 60.4, H
9.8, N 5.3.
6. Bartlett, P. A.; Otake, A. J. Org. Chem. 1995, 60, 3107–3111.
7. For examples, see: (a) Edmonds, M. K.; Abell, A. D. J. Org.
Chem. 2001, 66, 3747–3752; (b) Muhlman, A.; Lindberg, J.;
¨
Classon, B.; Unge, T.; Hallberg, A.; Samuelsson, B. J. Med.
Chem. 2001, 44, 3407–3416; (c) Xiao, J. B.; Weisblum, B.;
Wipf, P. J. Am. Chem. Soc. 2005, 127, 5742–5743.
8. (a) Jung, M. E.; Marquez, R. Org. Lett. 2000, 2, 1669–1672;
(b) Taylor, R. E.; Jin, M. Z. Org. Lett. 2003, 5, 4959–4961; (c)
Quintard, D.; Bertrand, P.; Bachmann, C.; Gesson, J. P. Eur.
J. Org. Chem. 2004, 4762–4770; (d) Ghosh, A. K.; Gong, G.
J. Am. Chem. Soc. 2004, 126, 3704–3705.
4.7.3. (S)-2-(tert-Butoxycarbonylamino)-4-methylpentanol
(S)-12b. Compound (S)-11b (27 mg, 0.10 mmol) was dis-
solved in MeOH (1.7 mL) and H2O (0.17 mL), and
K2CO3 (72 mg, 0.52 mmol) was added. The reaction was
stirred for 2 h, after which H2O (10 mL) and Et2O
(10 mL) were added and the layers were separated. The
aqueous phase was extracted with Et2O (10 mL) and the
combined organic phases were washed with brine
9. Ghanem, A.; Aboul-Enein, H. Y. Tetrahedron: Asymmetry
2004, 15, 3331–3351.
´
10. Garcıa-Urdiales, E.; Alfonso, I.; Gotor, V. Chem. Rev. 2005,
105, 313–354.
11. Tsuji, K.; Terao, Y.; Achiwa, K. Tetrahedron Lett. 1989, 30,
6189–6192.
12. Bertucci, C.; Petri, A.; Felix, G.; Perini, B.; Salvadori, P.
Tetrahedron: Asymmetry 1999, 10, 4455–4462.
(10 mL), dried over MgSO4, filtered, and concentrated to
13. Monteil, T.; Danvy, D.; Plaquevent, J. C.; Duhamel, L.;
Duhamel, P.; Gros, C.; Schwartz, J. C.; Lecomte, J. M. Synth.
Commun. 2001, 31, 211–218.
14. For a full explanation of lipase acronyms and trade names,
please see Section 4.2. ‘Materials’ of the experimental part.
15. The reported procedure was not suitable in our hands and the
reported chiral HPLC method did not give adequate resolu-
tion (Ref. 12).
16. (a) Lundhaug, K.; Overbeeke, P. L. A.; Jongejan, J. A.;
Anthonsen, T. Tetrahedron: Asymmetry 1998, 9, 2851–2856;
(b) Akeboshi, T.; Ohtsuka, Y.; Ishihara, T.; Sugai, T. Adv.
Synth. Catal. 2001, 343, 624–637.
20
give the title compound (19 mg, 83%). ½aꢁD ¼ ꢀ22
24
(ee 6 88%, c 0.95, CHCl3) {lit.30 ½aꢁD ¼ ꢀ26:8 (c 0.8,
1
CHCl3)}. The H and 13C NMR data were identical with
those reported.31
Acknowledgments
Financial support from the Knut and Alice Wallenberg
Foundation and the Swedish Research Council is gratefully
acknowledged. The authors thank Magnus J. Johansson
and Dr. Nina Kann (Chalmers University of Technology)
for the use of their chiral HPLC equipment and Professor
Stig Allenmark (Go¨teborg University) for his interest in
this work.
17. Sih, C. J.; Wu, S. H. Top. Stereochem. 1989, 19, 63–125.
18. Linear regression of ln[(1 ꢀ c(1 + eep))] versus ln[(1 ꢀ c(1-eep))]
yields a line with the slope E, since E = ln[(1 ꢀ c(1 + eep)]/
ln[(1 ꢀ c(1 ꢀ eep))], see also Refs. 17 and 19.
19. Keith, J. M.; Larrow, J. F.; Jacobsen, E. N. Adv. Synth.
Catal. 2001, 343, 5–26.
20. ‘E’ was calculated by the formula ‘E = ln{[1 ꢀ ees]/[1 + (ees/
eep)]}/ln{[1 + ees]/[1 + (ees/eep)]}’, see also Refs. 9 and 17.
21. Theil, F. Tetrahedron 2000, 56, 2905–2919.
References
22. Weissfloch, A. N. E.; Kazlauskas, R. J. J. Org. Chem. 1995,
60, 6959–6969.
1. (a) Roush, W. R.; Adam, M. A.; Peseckis, S. M. Tetrahedron
Lett. 1983, 24, 1377–1380; (b) Jackson, R. F. W.; Sutter, M.
A.; Seebach, D. Liebigs Ann. Chem. 1985, 2313–2327; (c)
Corey, E. J.; Bo, Y. X.; Busch-Petersen, J. J. Am. Chem. Soc.
1998, 120, 13000–13001; (d) Shattuck, J. C.; Shreve, C. M.;
23. (a) Mori, K.; Chiba, N. Liebigs Ann. Chem. 1989, 957–962;
(b) Guanti, G.; Banfi, L.; Narisano, E. Tetrahedron: Asym-
metry 1990, 1, 721–724; (c) Takabe, K.; Iida, Y.; Hiyoshi, H.;
Ono, M.; Hirose, Y.; Fukui, Y.; Yoda, H.; Mase, N.
Tetrahedron: Asymmetry 2000, 11, 4825–4829.
24. Santaniello, E.; Ferraboschi, P.; Grisenti, P. Tetrahedron
Lett. 1990, 31, 5657–5660.
25. For examples, see: (a) Guanti, G.; Narisano, E.; Podgorski,
T.; Thea, S.; Williams, A. Tetrahedron 1990, 46, 7081–7092;
(b) Banfi, L.; Guanti, G.; Riva, R. Tetrahedron: Asymmetry
Solomon, S. E. Org. Lett. 2001, 3, 3021–3023; (e) Brunjes, M.;
¨
Sourkouni-Argirusi, G.; Kirschning, A. Adv. Synth. Catal.
2003, 345, 635–642; (f) Paquette, L. A.; Guevel, R.; Saka-
moto, S.; Kim, I. H.; Crawford, J. J. Org. Chem. 2003, 68,
6096–6107; (g) Paterson, I.; Di Francesco, M. E.; Kuhn, T.
¨
´
Org. Lett. 2003, 5, 599–602; (h) Casas, J.; Sunden, H.;
´
Cordova, A. Tetrahedron Lett. 2004, 45, 6117–6119.
´
1995, 6, 1345–1356; (c) Egri, G.; Fogassy, E.; Novak, L.;
2. For examples, see: (a) Spaltenstein, A.; Carpino, P. A.;
Miyake, F.; Hopkins, P. B. Tetrahedron Lett. 1986, 27, 2095–
2098; (b) Boger, D. L.; Hong, J. Y. J. Am. Chem. Soc. 2001,
Poppe, L. Tetrahedron: Asymmetry 1997, 8, 547–557; (d)
Trost, B. M.; Corte, J. R.; Gudiksen, M. S. Angew. Chem.,
Int. Ed. 1999, 38, 3662–3664.