8
90 Journal of Natural Products, 2005, Vol. 68, No. 6
Liblikas et al.
was added to a mixture of nepetalactones (100 mg, 71% of cis-
trans- and 22% of trans-cis-nepetalactone) in 6 mL of hexane
during 20 min at -70 °C. After 10 min, a saturated solution
of tartaric acid in EtOH (1.2 mL) was added. The cooling bath
was removed, and the mixture was allowed to reach room
10-OAc: 1H NMR (CDCl
3
) δ 6.19 (1H, d, J ) 3.3 Hz), 5.96
(1Η, d, J ) 1.2 Hz), 2.33 (1H, m), 2.25 (1H, dd, J ) 3.3, 7.4
1
3
Hz), 2.06 (3H, s), 1.59 (3H, s), 1.01 (3H, d, J ) 7.0 Hz);
NMR (CDCl ) δ 169.8, 132.5, 114.2, 89.6, 42.6, 36.9, 36.4, 32.7,
3
C
30.6, 21.5, 17.1, 15.0.
1
temperature. Baeckstr o¨ m reagent (Na
2
SO
4
‚10H
2
O:Celite, 1:1,
6-OAc: H NMR (CDCl
3
) δ 6.04 (1H, d, J ) 3.6 Hz), 6.01
v/v) (0.75 g) was added, and when the color had changed from
gray to white, the reaction mixture was filtered. The organic
solution was further dried and the solvent evaporated. The
residue was subjected to chromatography to yield 52 mg (52%)
of cis-trans-nepetalactols.
(1H, d, J ) 1.3 Hz), 2.25 (1H, dd, J ) 3.3, 7.6 Hz), 2.08 (3H,
13
3
s), 1.59 (3H, s), 1.01 (3H, s); C NMR (CDCl ) δ 170.0, 134.5,
113.4, 90.9, 42.5, 38.8, 35.2, 32.2, 29.0, 21.3, 16.2, 16.0.
Acknowledgment. This work has received financial sup-
port from the Swedish Council for Forestry and Agricultural
Research, the Carl-Fredrik von Horn’s Foundation, the Hierta
Foundation, the Carl Trygger Foundation, and the Estonian
Science Foundation grant no. 5085 and project 0422104s02.
We thank Professors T. Norin and A.-K. Borg-Karlson for
helpful discussions and assistance.
Procedure 2. DIBAL (1.56 M solution in hexane, 1.5 mL,
2
.34 mmol) was added to a solution of cis-trans-nepetalactone
(
251 mg, 1.51 mmol) in 10 mL of hexane during 5 min at -70
C. After 2 h the cooling bath was removed and the mixture
was allowed to reach room temperature. Baeckstr o¨ m reagent
Na SO ‚10H O:Celite, 1:1, v/v) (2.5 g) was added, and when
°
(
2
4
2
the color had changed from gray to white, the mixture was
filtered. The organic solution was further dried and the solvent
evaporated. The residue was subjected to chromatography to
References and Notes
(1) Dawson, G. W.; Griffiths, D. C.; Janes, N. F.; Mudd, A.; Pickett, J.
A.; Wadhams, L. J.; Woodcock, C. M. Nature 1987, 325, 614-616.
yield 211 mg (83%) of cis-trans-nepetalactols.
(
2) Dawson, G. W.; Janes, N. F.; Mudd, A.; Pickett, J. A.; Slawin, A. M.
Z.; Wadhams, L. J.; Williams, D. J. Pure Appl. Chem. 1989, 61, 555-
558.
1
(
1R,4aS,7S,7aR)-Nepetalactol (9): H NMR (CDCl
3
) δ 6.00
(
1H, s), 4.84 (1Η, d, J ) 5.5 Hz), 2.93 (1H, s), 2.45 (1H, dd, J
7.6, 7.9 Hz), 1.87 (3H, m), 1.64 (1H, dd, J ) 6.4, 6.7 Hz),
.54 (3H, s), 1.36 (1H, m), 1.15 (1H, m), 1.07 (3H, d, J ) 6.4
(
3) Hardie, J.; Holyoak, M.; Nicholas, J.; Nottingham, S. F.; Pickett, J.
A.; Wadhams, L. J.; Woodcock, C. M. Chemoecology 1990, 1, 63-68.
4) Dawson, G. W.; Griffiths, D. C.; Merritt, A. L.; Mudd, A.; Pickett, J.
A.; Wadhams, L. J.; Woodwock, C. M. Ent. Exp. Appl. 1988, 48, 91-
93.
)
1
(
13
3
Hz); C NMR (CDCl ) δ 134.9, 113.7 (C4), 94.4 (C1), 50.5 (C7a
or 4a), 38.8 (C5), 35.8 (C7a or 4a), 33.3, 30.8, 20.6 (C8 or 9),
1
(
5) Dawson, G. W.; Griffiths, D. C.; Merritt, L. A.; Mudd, A.; Pickett, J.
A.; Wadhams, L. J.; Woodcock, C. M. J. Chem. Ecol. 1990, 16, 3019-
6.3 (C8 or 9).
Synthesis of cis-cis-Nepetalactols 6 and 10. DIBAL
3
029.
(
1.56 M solution in hexane, 1.5 mL, 2.34 mmol) was added to
(6) Hardie, J.; Storer. J. R.; Nottingham, S. F.; Peace, L.; Harrington,
R.; Merritt, L. A.; Wadhams, L. J.; Wood, D. K. Proc. Br. Crop Prot.
Conf. Pests Dis. 1994, 1223-1230.
a solution of cis-cis-nepetalactone (340 mg, 2.05 mmol) in 10
mL of hexane during 5 min at -70 °C. After 2 h the cooling
bath was removed and the mixture was allowed to reach room
(
7) Goldansaz, S. H.; Dewhirst, S.; Birkett, M. A.; Hooper, A. M.; Smiley,
D. W. M.; Pickett, J. A.; Wadhams, L. J.; McNeil, J. J. Chem. Ecol.
2004, 30, 819-834.
2 4 2
temperature. Baeckstr o¨ m reagent (Na SO ‚10H O:Celite, 1:1,
v/v) (2.5 g) was added, and when the color had changed from
gray to white, the mixture was filtered. The organic solution
was further dried and the solvent evaporated. The residue was
subjected to chromatography to yield 300 mg (87%) of cis-
(8) Campbell, C. A. M.; Dawson, G. W.; Griffiths, D. C.; Pettersson, J.;
Pickett, J. A.; Wadhams, L. J.; Woodcock, C. M. J. Chem. Ecol. 1990,
1
6, 3455-3465.
(
9) Dawson, G. W.; Pickett, J. A.; Smiley, D. W. M. Bioorg., Med. Chem.
1996, 4, 351-361.
(
10) Hardie, J.; Peace, L.; Pickett, J. A.; Smiley, D. W. M.; Storer, J. R.;
Wadhams, L. J. J. Chem. Ecol. 1997, 23, 2547-2554.
11) Bates, R. B.; Sigel, C. W. Experientia 1963, 564-565.
12) Sakurai, K.; Ikeda, K.; Mori, K. Agr. Biol. Chem. 1988, 52, 2369-
2371.
cis-nepetalactols 6 and 10.
1
6
: H NMR (CDCl
3
) δ 6.01 (1H, dd, J ) 1.2, 1.4 Hz), 5.01
(
(
(
1Η, t, J ) 5.8 Hz), 2.85 (1H, d, J ) 5.8 Hz), 2.46 (1H, dd, J )
.3, 7.6 Hz), 2.21 (2H, m), 2.14 (1H, m), 1.79 (3H, m), 1.54
7
1
3
(13) Nangia, A.; Prasuna, G.; Rao, B. Tetrahedron 1997, 53, 14507-14545.
(
(
(
2
3H, s), 1.30 (1H, m), 1.08 (3H, dd, J ) 3.1, 7.0 Hz); C NMR
CDCl ) δ 169.8, 132.5, 114.2, 89.6, 42.6, 36.9, 36.4, 32.7, 30.6,
1.5, 17.1, 15.0.
14) Bottini, A. T.; Dev, V.; Garfagnoli, D. J.; Lohani, H.; Mathela, C. S.;
3
Pant, A. K. Phytochemistry 1987, 26, 1200-1202.
(15) Trave, R.; Marchesini, A.; Garanti, L. Gaz. Chim. Ital. 1968, 1132-
1
1
0: H NMR (CDCl
3
) δ 5.98 (1H, dd, J ) 1.2, 1.5 Hz), 5.32
1151.
(
16) Velasco-Negueruela, A.; Perez-Alonso, M. J.; Rodriquez, A. B. Flavour
Fragr. J. 1989, 4, 197-199.
(
1H, t, J ) 3.4 Hz), 2.64 (1H, dd, J ) 4.6, 7.6 Hz), 2.14 (2H,
1
3
3
m), 2.0 (2H, m), 1.79 (1H, m), 1.59 (3H, s); C NMR (CDCl )
(17) Baeckstr o¨ m, P.; Jir o´ n, Z. Proceedings of the World Neem Conference,
Bangalore, India. Feb. 24-28, 1993.
δ 170.0, 134.5, 113.4, 90.9, 42.5, 38.8, 35.2, 32.2, 29.0, 21.3,
1
6.2, 16.0.
(18) Jir o´ n, Z. Approaching Optimal Conditions for Running Liquid
Adsorption Column Chromatography Using Simple Computational
Models. Ph.D. Thesis, Royal Institute of Technology, Stockholm,
Sweden, 1996.
(19) De Pooter, H. L.; Nicolai, B.; de Buyck, L. F.; Goetghebeur, P.;
Schamp, N. M. Phytochemistry 1987, 26, 2311-14.
Synthesis of cis-cis-Nepetalactyl Acetate. Procedure
. DIBAL (1.56 M solution in hexane, 1.3 mL, 2.03 mmol) was
1
added to cis-cis-nepetalactone 10/6 (250 mg, 1.5 mmol) in 13
mL of hexane for 20 min at -70 °C. After stirring for 0.5 h,
(
20) Sakan, T.; Isoe, S.; Hyeon, S. B.; Katsumura, R.; Maeda, T. Tetra-
hedron Lett. 1965, 46, 4097-4102.
2
Ac O (1.0 g, 9.8 mmol), DMAP (366 mg, 3 mmol), and pyridine
(
1.5 mL) were added at -70 °C. The mixture was allowed to
(
21) Becke, A. D. Phys. Rev. A 1988, 38, 3098-3100.
reach RT overnight. Workup and chromatography yielded 300
(22) Becke, A. D. J. Chem. Phys. 1993, 98, 5648-5652.
(
(
23) Lee, C.; Yang, W.; Parr, R. G. Phys. Rev. B 1988, 37, 785-789.
24) Eisenbraun, E. J.; Browne, C. E.; Irvin-Willis, R. L.; McGurk, D. J.;
Eliel, E. L.; Harris, D. L. J. Org. Chem. 1980, 45, 3811-3814.
mg (95%) of a 30/70 mixture of cis-cis-nepetalactyl acetates
(
the 6-OAc dominating as determined by GC).
Procedure 2. A sample of the above cold reaction mixture
(25) Murai, F.; Motoko, T.; Damtoft, S.; Jensen, S. R.; Nielsen, B. J. Chem.,
Pharm. Bull. 1984, 32, 2809-2814.
(
was allowed to reach room temperature before the acetylating
reagents were added. This procedure gave a 10/90 mixture of
cis-cis-nepetalactyl acetates and more byproducts than pro-
cedure 1.
26) Baeckstr o¨ m, P.; Stridh, K.; Li, L.; Norin, T. Acta Chem. Scand. B
1
987, 41, 442-447.
NP049647D