First synthesis of ( )ꢀvertilecanin A
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 10, October, 2005
2467
13.3 mmol) in a water—dioxane (1 : 9) mixture (13 mL,
~1 M H2О). The reaction mixture was refluxed for 24 h. After
cooling to room temperature, the reaction mixture was poured
onto 30 g of ice. The organic components were extracted with
AcOEt (3×30 mL), and the extract was dried with Na2SO4.
After the solvent was removed, acid 9 was obtained in a yield of
2.34 g (77%) as white crystals, m.p. 128—130 °С (from CHCl3).
1H NMR (200 MHz, CDCl3), δ: 9.73 (br.s, 1 H, COOH); 9.07
(br.s, 1 H, H(6)); 8.37 (br.d, A part of AB system, 1 H, H(3) or
H(4), J3,4 = 8.1 Hz); 8.32 (dd, B part of AB system, 1 H, H(3) or
H(4), J3,4 = 8.1 Hz, 4J = 1.8 Hz); 7.82 (dm, 2 H, H arom., J =
7.7 Hz); 7.73—7.64 (m, 1 H, H arom.); 7.54 (tm, 2 H, H arom.,
J = 7.7). 13C NMR (50 MHz, CDCl3), δ: 193.5, 163.7, 149.2,
148.4, 139.4, 136.8, 136.0, 133.9, 130.1, 128.9, 123.7. IR (KBr),
ν/cm–1: 3063, 3026, 2873, 2624, 1713, 1665, 1597, 1579, 1476,
1448, 1384, 1246, 1122, 1033. Mass spectrum, m/z (Irel (%)):
184.0 [M+ – CO2] (12), 182.9 [M+ – CO2] (100), 181.9
[M+ – CO2H] (42), 105.9 (16), 104.9 (72), 77.9 (18), 76.8 (46).
for (–)ꢀ1: m.p. 155—157 °С). 1H NMR (400 MHz, acetoneꢀd6),
δ: 8.75 (br.s, 1 H, H(6)); 8.11 (d, A part of AB system, 1 H,
H(3), J3,4 = 8.1 Hz); 8.06 (dd, B part of AB system, 1 H, H(4),
J3,4 = 8.1 Hz, J3,6 = 1.8 Hz); 7.47 (br.d, 2 H, J = 7.3 Hz); 7.35
(br.t, 2 H, J = 7.3 Hz); 7.27 (br.t, 1 H, J = 7.3 Hz); 6.06 (s, 1 H,
CH—OH). 13С NMR (100 MHz, acetoneꢀd6), δ: 164.8, 147.4,
146.1, 145.4, 144.3, 135.8, 128.7, 127.8, 126.7, 123.9, 73.0.
The authors thank Professor Dr. J. B. Gloer for sendꢀ
ing the original NMR spectrum of (–)ꢀvertilecanin A for
comparison, Dr. H. Kilic for recording the EIMS spectra,
and Dr. C. Kazaz for obtaining the NMR spectra of
vertilecanin A.
References
1. A. G. Soman, J. B. Gloer, R. F. Angawi, D. T. Wicklow, and
P. F. Dowd, J. Nat. Prod., 2001, 64, 189.
(
)ꢀ5ꢀ[(Hydroxy)(phenyl)methyl]pyridineꢀ2ꢀcarboxylic acid
(vertilecanin A) (1). A solution of ketone 9 (0.5 g, 2.2 mmol) in
MeOH (10 mL) was added dropwise at 0 °С to a magnetically
stirred suspension of NaBH4 (0.1 g, 2.7 mmol) in MeOH
(30 mL). After the addition was completed, the mixture was
stirred at room temperature for 12 h. Then MeOH was distilled
off under reduced pressure, and water (10 mL) was added. The
organic components were extracted with AcOEt (3×30 mL),
and the extracts were dried with Na2SO4. Removal of the solꢀ
vent and recrystallization from MeOH gave ( )ꢀvertilecanin A
as colorless crystals (0.420 g, 83%), m.p. 155—157 °С (cf. Ref. 1
2. F. J. Villani and M. S. King, Organic Syntheses. Coll. Vol. 4,
Wiley, New York, 1966, 88.
3. E. Langhals, H. Langhals, and C. Ruchardt, Liebigs Ann.
Chem., 1982, 930.
4. L. E. Fisher, J. M. Caroon, S. R. Stabler, S. Lundberg,
S. Zaidi, C. M. Sorensen, M. L. Sparacino, and J. M.
Muchowski, Can. J. Chem., 1994, 72, 142.
Received June 16, 2004