3
196
References
1
. (a) Faber, K. In Biotransformations in Organic Chemistry; Springer Verlag: Germany, 3rd ed., 1997. (b) Anderson, E. M.;
Larsson, K. M.; Kirk, O. Biocatal. Biotransform. 1998, 16, 181–204. (c) Rotticci, D.; Hæffner, F.; Orrenius, C.; Norin, T.;
Hult, K. J. Mol. Catal. B, Enzymatic 1998, 5, 267–272.
2
. (a) Nordin, O.; Nguyen, B.-V.; Vörde, C.; Hedenström, E.; Högberg, H.-E. J. Chem. Soc., Perkin Trans. 1 2000, 367–376.
(b) Franssen, M. C. R.; Jongejan, H.; Kooijman, H.; Spek, A. L.; Camacho Mondril, N. L. F. L.; Boavida dos Santos, P. M.
A. C.; de Groot, Ae. Tetrahedron: Asymmetry 1996, 7, 497–510. (c) Enzymatic Reactions in Organic Media; Koskinen, A.
M. P.; Klibanov, A. M., Eds.; Blackie: UK, 1996.
3
4
. Osprian, I.; Steinreiber, A.; Mischitz, M.; Faber, K. Biotechnol. Lett. 1996, 18, 1331–1334.
. Franssen, M. C. R.; Jongejan, H.; Kooijman, H.; Spek, A. L.; Bell, R. P. L.; Wijnberg, J. B. P. A.; de Groot, Ae. Tetrahedron:
Asymmetry 1999, 10, 2729–2738.
5
. (a) Lindmark, M.; Isaksson, D.; Sjödin, K.; Högberg, H.-E., in press. (b) Compound 2 can be efficiently resolved by acylation
with vinyl acetate catalysed by Candida rugosa lipase (CRL) in diisopropyl ether (Ref. 4) and is a key intermediate for the
synthesis of the marasmane and lactarane sesquiterpenes: see: Ref. 4 and Bell, R. P. L.; Sobolev, A.; Wijnberg, J. B. P. A.;
de Groot, Ae. J. Org. Chem. 1998, 63, 122–128.
™
6
7
. The 1-Ac formed was of low ee and varying configuration depending on the enzyme used. Thus Chirazyme L6 and
Novozyme 435 gave (−)-1-Ac (E∼2) and (+)-1-Ac (E∼1.5), respectively.
. (a) Franssen, M. C. R.; Goetheer, E. L. V.; Jongejan, H.; de Groot, Ae. Tetrahedron Lett. 1998, 39, 8345–8348. (b) Angelis
Y.S.; Smnou, I. Tetrahedron Lett. 1997, 38, 8109–8112. (c) ibid 1998, 39, 2823–2826.
8
9
. Boiled in water for 5 min, after which the water was removed by evaporation in vacuo.
. The enantiopreference of CALB in this reaction is opposite to that of Candida rugosa lipase in the formation of 2-Ac (Ref.
4
).
1
1
0. Many lipases hydrolyse vinyl acetate, even under ‘dry’ conditions: Weber, H. K.; Weber, H.; Kazlauskas R. J. Tetrahedron:
Asymmetry 1999, 10, 2635–2638.
1
1. Hemiacetal ester 3 from (−)-borneol, (−)-1: Colourless oil. H NMR (C
6 6
D ): δ 0.76 (s, 3H), 0.78 (s, 3H), 0.92 (s, 3H), 1.05
(dd, 1H, J=13.0, 3.4 Hz), 1.18 (m, 1H), 1.25 (m, 1H), 1.32 (d, 3H, J=5.2 Hz), 1.55 (t, 1H, J=4.6 Hz), 1.66 (m, 1H), 1.75 (s,
1
3
3
2
6 6
H), 2.17 (m, 2H), 3.95 (ddd, 1H, J=9.5, 3.2, 1.8 Hz), 6.06 (q, 1H, J=5.2 Hz). C NMR (C D ): δ 13.62, 18.89, 19.82, 21.10,
+
1.37, 26.83, 28.52, 36.37, 45.32, 47.75, 49.10, 82.59, 94.92, 170.29. MS: 180 (peak with highest m/z, M −CH
3
COOH).
): δ 0.76 (s, 3H), 0.77 (s, 3H),
1
Hemiacetal ester 3 from (+)-borneol, (+)-1: colourless oil, by prep. LC. H NMR (C
6
D
6
0
1
.84 (s, 3H), 1.15 (dd, 1H, J=13.0, 3.4 Hz), 1.25 (m, 1H), 1.28 (m, 1H), 1.32 (d, 3H, J=5.2 Hz), 1.53 (t, 1H, J=4.6 Hz),
1
3
6 6
.68 (m, 1H), 1.77 (s, 3H), 2.13 (m, 2H), 3.89 (ddd, 1H, J=9.5, 3.2, 1.8 Hz), 6.05 (q, 1H, J=5.2 Hz). C NMR (C D ):
δ 13.76, 18.86, 19.75, 21.19, 21.08, 26.93, 28.47, 37.47, 45.38, 47.31, 49.58, 85.97, 97.44, 169.96. MS: 180 (peak with
+
1
highest m/z, M −CH
3
COOH). Hemiacetal ester 4 from racemic 2: colourless oil, by prep. GC. H NMR (C
6
D
6
): δ 0.93
(
s, 6H); 1.14 and 1.19 (s, 3H, two isomers); 1.35 and 1.38 (d, 3H, J=5.1 Hz, two isomers); 1.43–2.22 (m, 10H); 1.73 and
.74 (s, 3H, two isomers), 3.65 (m, 1H, two isomers); 5.39 (m, 1H); 6.21 (q, 1H, J=5.1 Hz). C NMR (C
8.41, 19.10, 19.30, 20.84, 21.08, 21.47, 25.18, 25.45, 26.17, 31.91, 32.00, 32.29, 36.21, 36.44, 39.23, 40.21, 43.07, 45.31,
5.52, 80.77 and 85.17 (C1), 93.10 and 97.83 (O–C–O), 123.90 (C5), 140.18 and 140.43 (C4a), 170.00 and 170.21 (C_O).
HRMS: theor. C15
GC. H NMR (C
isomers), 6.22 (m, 1H, two isomers). C NMR (C
1
3
1
1
4
6
D
6
): δ 18.31,
+
H
24O (M −CH
3
COOH): 220.1827; found: 220.1818. Hemiacetal ester from 7: colourless oil, by prep.
1
6
D
6
): δ 0.84–2.10 (m, 16H), 1.36 (d, 3H, J=5.4 Hz), 1.70 and 1.71 (s, 3H, two isomers), 3.66 (m, 1H, two
13
6
6
D ): δ 19.89, 20.78, 21.29, 21.41, 21.52, 24.47, 24.57, 26.24, 26.38,
2
6.53, 27.68, 31.83, 35.57, 35.84, 39.84, 42.31, 79.69 and 80.43 (C1), 94.24 and 95.17 (O−C−O), 170.29 (C_O). HRMS:
+
1
theor. C12
H
20O (M −CH
3
COOH): 180.1514, found: 180.1511. Hemiacetal ester from 8: colourless oil, by prep. GC; H
), 4.74 (m, 1H, two
): δ 14.10, 18.56,
8.86, 19.01, 20.71, 20.85, 21.18, 21.37, 22.54, 28.49, 28.71, 28.94, 29.10, 30.20, 73.37 and 75.16 (C1), 94.02 and 95.89
O–C–O), 125.83–137.54 (6 aromatic carbons atoms, overlapped by the solvent), 169.94 and 170.17 (C_O). HRMS: theor.
NMR (C
6
D
6
): δ 1.31 and 1.38 (2×d, 3H, J=5.1 Hz, two isomers); 1.40–2.72 (m, 6H); 1.73 (s, 3H CH
3
1
3
isomers); 6.28 and 6.38 (q, 1H, J=5.1 Hz, two isomers); 6.90–7.70 (m, 4H). C NMR (two isomers, C D
6 6
1
(
C
+
12
H
14O (M −CH
3
COOH): 174.1045; found: 174.1041.