R. A. Davis, M. Kotiw / Tetrahedron Letters 46 (2005) 5199–5201
5201
fractions combined to yield pure (ꢀ)-dechloroxylariamide
(ꢀ)-xylariamide A (1, 43 mg, 78%) as a stable clear
23
23
24
A (6, 142.6 mg, 54%) as a stable clear gum; ½aꢁD ꢀ15 (c
gum; ½aꢁD ꢀ16 (c 0.250, CH3OH) (lit. ½aꢁD ꢀ22 (c 0.060,
CH3OH));1 UV (CH3OH) kmax (loge) 208 (4.01), 220 sh
(3.93), 276 (3.36) nm; IR mmax (NaCl) 3500–3200, 1712,
1665, 1549, 1512, 1440, 1345, 1294, 1237, 1196, 1173, 1057,
0.270, CH3OH); UV (CH3OH) kmax (loge) 214 (4.01), 265
(3.58) nm; IR mmax (NaCl) 3600–3100, 1720, 1664, 1546,
1516, 1445, 1349, 1308, 1272, 1232, 1198, 1173, 1113, 1024,
979, 832, 766 cmꢀ1
;
1H NMR (500 MHz, DMSO-d6) d
1024, 976, 824, 766, 667 cmꢀ1 1H NMR (500 MHz,
;
2.76 (1H, dd, J = 14.0, 9.5 Hz, H-7a), 2.98 (1H, dd,
J = 14.0, 5.0 Hz, H-7b), 3.71 (3H, s, 13-OCH3), 4.44 (1H,
ddd, J = 9.5, 7.5, 5.0 Hz, H-8), 6.53 (1H, d, J = 15.5 Hz,
H-12), 6.64 (2H, d, J = 8.5 Hz, H-3, H-5), 7.00 (2H, d,
J = 8.5 Hz, H-2, H-6), 7.06 (1H, d, J = 15.5 Hz, H-11),
8.79 (1H, d, J = 7.5 Hz, 8-NH), 9.18 (1H, br s, 4-OH),
12.76 (1H, br s, 9-OH); 13C NMR (125 MHz, DMSO-d6) d
35.9 (C-7), 51.9 (13-OCH3), 54.1 (C-8), 115.0 (2C, C-3, C-
5), 127.3 (C-1), 128.5 (C-12), 129.9 (2C, C-2, C-6), 137.1
(C-11), 155.9 (C-4), 162.6 (C-10), 165.4 (C-13), 172.5 (C-
9); (ꢀ)-LRESIMS m/z (rel int.) 134 (10), 216 (5), 248 (5),
278 (5), 292 (100); (ꢀ)-HRESIMS m/z 292.08401
(C14H14NO6 [MꢀH]ꢀ requires 292.08268).
DMSO-d6) d 2.78 (1H, dd, J = 14.0, 9.0 Hz, H-7a), 2.99
(1H, dd, J = 14.0, 5.0 Hz, H-7b), 3.71 (3H, s, 13-OCH3),
4.46 (1H, ddd, J = 9.0, 8.5, 5.0 Hz, H-8), 6.54 (1H, d,
J = 15.5 Hz, H-12), 6.84 (1H, d, J = 8.5 Hz, H-5), 6.97 (1H,
dd, J = 8.5, 1.5 Hz, H-6), 7.05 (1H, d, J = 15.5 Hz, H-11),
7.17 (1H, d, J = 1.5 Hz, H-2), 8.80 (1H, d, J = 8.5 Hz, 8-
NH), 9.94 (1H, br s, 4-OH), 12.82 (1H, br s, 9-OH), 13C
NMR (125 MHz, DMSO-d6) d 35.5 (C-7), 52.0 (13-OCH3),
53.8 (C-8), 116.4 (C-5), 119.1 (C-3), 128.6 (2C, C-6, C-12),
128.9 (C-1), 130.2 (C-2), 136.9 (C-11), 151.6 (C-4), 162.7
(C-10), 165.4 (C-13), 172.3 (C-9); (ꢀ)-LRESIMS m/z (rel
int.) 168 (20), 170 (7), 250 (10), 252 (3), 282 (10), 284 (3),
312 (10), 314 (3), 326 (100), 328 (33); (ꢀ)-HRESIMS m/z
326.04252 (C14H13NO635Cl [MꢀH]ꢀ requires 326.04369).
8. Skehan, P.; Storeng, R.; Scudiero, D.; Monks, A.;
McMahon, J.; Vistica, D.; Warren, J. T.; Bokesch, H.;
Kenney, S.; Boyd, M. R. J. Natl. Cancer Inst. 1990, 82,
1107–1112.
9. Jorgensen, J. H.; Weigel, L. M.; Swenson, J. M.; Whitney,
C. G.; Ferraro, M. J.; Tenover, F. C. Antimicrob. Agents
Chemother. 2000, 44, 2962–2968.
10. Lister, P. D. Antimicrob. Agents Chemother. 2002, 46, 69–
74.
11. Niwayama, S. J. Org. Chem. 2000, 65, 5834–5836.
12. Dymicky, M.; Buchanan, R. L. Org. Prep. Proced. Int.
1985, 17, 121–131.
13. Andruszkiewicz, R.; Chmara, H.; Milewski, S.; Borowski,
E. Int. J. Pept. Protein Res. 1986, 27, 449–453.
6. Ghosh, A. K.; Swanson, L. J. Org. Chem. 2003, 68, 9823–
9826.
7. Oxone (105 mg, 0.171 mmol) was added to (ꢀ)-dechlor-
oxylariamide A (6, 50 mg, 0.171 mmol) in CH3CN (5 mL)
and H2O (15 mL) then KCl (20 mg, 0.257 mmol) was
added in two equal portions over 1 h and the reaction
mixture was stirred at rt for 72 h, then poured into 2 N HCl
(50 mL), saturated with NaCl then extracted with EtOAc
(2 · 50 mL). The EtOAc layer was evaporated to dryness
under reduced pressure to yield a yellow gum (76 mg). This
material was dissolved in DMSO (750 lL) and CH3OH
(250 lL) and purified by preparative HPLC on a Thermo
˚
Hypersil C18 BDS 5 lm 143 A column (21.2 · 150 mm)
using isocratic conditions of 40% CH3OH/60% aqueous
TFA (0.2%) at a flow rate of 6 mL/min. This yielded pure