M. Hartl, H.-U. Humpf / Tetrahedron: Asymmetry 11 (2000) 1741±1747
1747
4
.3.3. (S)-(^)-Malic acid dinaphthylester (S)-6
Reaction was performed in acetonitrile as solvent. Excess of 2-naphthol was removed by prep-
arative TLC [silica gel, chloroform:methanol (14:2)] and the product was further puri®ed by
+
1
HPLC (Eurospher 100 C18, acetonitrile/water, UV 222 nm). ESI-MS m/z: 404 [M+NH ] . H
4
NMR (CDCl ): ꢀ 3.38 (2H, dd, J=5.2/4.8 Hz), 4.94 (1H, dd, J=4.8 Hz), 7.30 (2H, d, J=8.8 Hz),
3
7
.50 (4H, t, J=5.2 Hz), 7.63 (2H, s), 7.81 (2H, d, J=7.4 Hz), 7.88 (4H, d, J=8.8 Hz) ppm.
4
.3.4. (R)-(+)-Malic acid dinaphthylester (R)-6
Residual 2-naphthol was separated from the product by preparative TLC [silica gel, chloroform:
methanol (14:2)] and further puri®cation was achieved by HPLC (Eurospher 100 C18, acetonitrile/
+
1
water, UV 222 nm). ESI-MS m/z: 404 [M+NH ] . H NMR (CDCl ): ꢀ 3.38 (2H, dd, J=5.5/5.0
4
3
Hz), 4.94 (1H, dd, J=4.8 Hz), 7.30 (2H, d, J=8.8 Hz), 7.50 (4H, t, J=5.2 Hz), 7.63 (2H, s), 7.81
(2H, d, J=8.1 Hz), 7.88 (4H, d, J=8.8 Hz) ppm.
4
.3.5. Abietic acid naphthylester 8
The product was separated from residual 2-naphthol by preparative TLC on silica gel plates
[
using an acetonitrile/water gradient and UV detection at 222 nm. EI-HRMS m/z for C H O
diethyl ether:pentane (1:1)]. Further puri®cation was by HPLC on a Eurospher 100 C18 column
30
36
2
1
calcd 428.2715, found 428.2717. H NMR (CDCl ): ꢀ 0.90 (3H, s), 1.02 (3H, d, J=7.0 Hz), 1.04
3
(3H, d, J=6.6 Hz), 1.42 (3H, s), 5.48 (1H, m), 5.82 (1H, s), 7.16 (1H, d, J=8.8 Hz), 7.45 (1H, t,
J=7.0 Hz), 7.47 (1H, s), 7.49 (1H, t, J=6.8 Hz), 7.80 (1H, d, J=8.6 Hz), 7.84 (2H, d, J=8.8 Hz)
ppm.
References
1
2
. Harada, N.; Nakanishi, K. Circular Dichroic Spectroscopy±Exciton Coupling in Organic Stereochemistry;
University Science Books: Mill Valley, 1983.
. Nakanishi, K.; Berova, N. In Circular DichroismÐPrinciples and Applications; Nakanishi, K.; Berova, N.; Woody,
R. W., Eds. The exciton chirality method. VCH: New York, 1994; pp. 361±398.
3
4
. Zhou, P.; Berova, N.; Wiesler, W. T.; Nakanishi, K. Tetrahedron 1993, 49, 9343±9352.
. Harada, N.; Saito, A.; Ono, H.; Murai, S.; Li, H.-Y.; Gawronski, J.; Gawronska, K.; Sugioka, T.; Uda, H.
Enantiomer 1996, 1, 119±138.
5
. Akritopoulou-Zanze, I.; Nakanishi, K.; Stepowska, H.; Grzeszczyk, B.; Zamojski, A.; Berova, N. Chirality 1997,
9, 699±712.
6
7
8
9
. Hartl, M.; Humpf, H.-U. Tetrahedron:Asymmetry 1998, 9, 1549±1556.
. Rickman, B.; Matile, S.; Nakanishi, K.; Berova, N. Tetrahedron 1998, 54, 5041±5064.
. Gimple, O.; Schreier, P.; Humpf, H.-U. Tetrahedron: Asymmetry 1997, 8, 11±14.
È
. Hor, K.; Gimple, O.; Schreier, P.; Humpf, H.-U. J. Org. Chem. 1998, 63, 322±325.
1
1
1
1
0. Diago-Meseguer, J.; Palomo-Coll, A. L.; Fernandez-Lizarbe, J. R.; Zugaza-Bilbao, A. Synthesis 1980, 547±551.
1. According to the Plat classi®cation, for a description see Ref. 1, pp. 41±42.
2. Wiesler, W. T.; Nakanishi, K. J. Am. Chem. Soc. 1989, 111, 9205±9213.
3. All calculations were carried out with MM2 force ®eld in CHCl
simulation.
3
; at least 1000 conformers were searched for each
1
È
4. Hor, K.; Hartl, M.; Walford, B.; Gutsche, B.; Schreier, P.; Humpf, H.-U. In Natural Product Analysis; Schreier, P.;
Herderich, M.; Humpf, H.-U.; Schwab, W., Eds. A new approach in exciton coupled circular dichroism:
stereochemical assignment of natural products containing carboxyl groups. Vieweg: Wiesbaden, 1998; pp. 223±
2
29.