A. Ben et al. / Tetrahedron 67 (2011) 6460e6468
6467
J¼11.4 Hz), 4.72 (d,1H, J¼11.4 Hz), 4.35 (d,1H, J¼10.4 Hz), 4.17 (q,1H,
J¼6.3 Hz), 4.08 (s, 3H), 3.99 (s, 3H), 3.99 (dd, 1H, J¼2.9, 9.7 Hz), 3.92
(dd, 1H, J¼8.7, 9.7 Hz), 3.78 (br d, 1H, J¼2.9 Hz), 3.53 (d, 1H,
J¼10.4 Hz), 2.52 (s, 3H), 1.32 (d, 3H, J¼6.3 Hz); 13C NMR (100 MHz,
13C NMR (125 MHz, DMSO-d6)
d
159.7, 157.0, 153.5, 151.8, 141.9,
140.5, 129.5, 126.7, 125.0, 121.6, 121.2, 120.9, 119.1, 115.2, 113.5, 111.8,
101.8, 79.5, 75.7, 69.9, 69.3, 66.1, 56.6, 56.3, 41.9, 40.1, 21.1, 17.0; IR
(KBr) 1712 (CO) cmꢀ1; HRMS (FAB) m/z calcd for C28H32O8N (MHþ)
510.2128. Found: 510.2125.
CDCl3)
d 160.6, 157.2, 155.5, 152.9, 142.1, 139.7, 138.4, 137.5, 137.3,
128.4, 128.29, 128.28, 128.1, 127.71, 127.67, 127.5, 127.3, 127.1, 126.8,
125.4, 122.6, 122.24, 122.16,119.0, 118.1, 114.8,110.1, 105.5, 81.2, 79.5,
78.3, 75.6, 75.3, 73.9, 71.7, 68.0, 56.9, 56.3, 21.6, 17.3; IR (KBr) 2098
(N3),1722 (CO) cmꢀ1. Anal. Calcd for C47H43N3O8: C, 72.57; H, 5.57; N,
5.40. Found: C, 72.32; H, 5.51; N, 5.14.
4.1.15. Deacetylravidomycin M N-oxide (1a). To a stirred solution of
deacetylravidomycin M (1) (3.4 mg, 6.7 mmol) in CH2Cl2 (1.0 mL)
was added m-CPBA (1.2 mg, 7.0 mmol) at room temperature. After
stirring for 0.5 h, purification by column chromatography (Chro-
matorex NH-DM1020, Fujisilysia Chemical LTD, CHCl3/MeOH¼30/
1) gave N-oxide 1a (3.4 mg, 97%.) as yellow powders: Rf 0.62
(Chromatorex NH-DM1020; CHCl3/MeOH¼10/1); mp 202e204 ꢁC
4.1.13. Dimethylamine (20). To a stirred solution of lactone 19
(22.6 mg, 29.1 mmol) in toluene (5.0 mL) was added 1 M toluene
solution of PMe3 (0.15 mL, 0.15 mmol) at room temperature. After
stirring for 1.7 h, the solvent was removed in vacuo, and the residue
was dissolved in CH2Cl2. Paraformaldehyde (11.3 mg, 0.38 mmol)
was added, and the mixture was stirred for 3 h. Water-containing
THF [water/THF¼1/9 (v/v)] was added, and the stirring was con-
tinued for 2 h. After addition of water, the mixture was extracted
with CH2Cl2 (ꢃ3), and the combined organic extracts were washed
with brine and dried over Na2SO4. After filtration, the solvents were
removed in vacuo, and the residue was dissolved in CH3CN (2 mL),
and formalin (0.3 mL) was added. After stirring for 0.5 h, acetic acid
(0.1 mL) and NaBH3CN (12.0 mg, 0.19 mmol) were added at room
temperature, and the stirring was continued for 15 h. The reaction
was quenched by adding satd aqueous NaHCO3 solution at 0 ꢁC. The
mixture was extracted with EtOAc (ꢃ3), and the combined organic
extracts were washed with brine and dried over Na2SO4. After fil-
tration, removal of the solvents in vacuo and purification by silica-
gel column chromatography (CHCl3/MeOH¼30/1) afforded dime-
thylamine 20 (15.2 mg, 67%) as yellow powder: Rf 0.40 (CHCl3/
(decomp.);
½
a 2D2
ꢂ
þ45 (c 0.36, CHCl3/MeOH¼1/1); 1H NMR
(500 MHz, DMSO-d6)
d
9.84 (br s, 1H), 8.45 (s, 1H), 7.84 (d, 1H,
J¼8.4 Hz), 7.74 (br s, 1H), 7.46 (br s, 1H), 6.95 (d, 1H, J¼8.4 Hz), 5.65
(d, 1H, J¼8.9 Hz), 4.58 (dd, 1H, J¼8.9, 10.4 Hz), 4.12 (q, 1H, J¼6.4 Hz),
4.08 (s, 3H), 4.07 (3H, s), 4.06 (br d, 1H, J¼2.7 Hz), 3.47 (dd, 1H,
J¼2.7, 10.4 Hz), 3.33 (s, 3H), 3.18 (3H, s), 2.48 (s, 3H), 1.00 (d, 3H,
J¼6.4 Hz); 13C NMR (125 MHz, DMSO-d6)
d 159.8, 157.1, 153.7, 151.9,
141.9, 140.6, 129.7, 125.3, 125.2, 121.6, 121.3, 120.9, 119.2, 115.3, 113.7,
111.8, 101.8, 80.3, 79.7, 75.1, 68.0, 66.7, 57.6, 56.6, 56.3, 55.1, 21.1,
16.8; IR (KBr) 1711 (CO) cmꢀ1; HRMS (FAB) m/z calcd for C28H32O9N
(MHþ) 526.2077. Found: 526.2090.
Acknowledgements
This work supported by the Hayashi Memorial Foundation for
Female Natural Scientists. Partial financial support was provided by
21st Century COE program (Tokyo Institute of Technology).
MeOH¼10/1); mp 95e98 ꢁC; ½a D22
ꢂ
ꢀ173 (c 1.02, CHCl3); 1H NMR
References and notes
(500 MHz, CDCl3)
d
8.37 (s,1H), 8.05 (d,1H, J¼8.4 Hz), 7.90 (br s,1H),
7.59 (br d, 2H, J¼7.6 Hz), 7.49 (d, 2H, J¼7.2 Hz), 7.41e7.36 (m, 4H),
7.33e7.29 (m, 2H), 7.15 (d, 1H, J¼8.4 Hz), 7.14 (br s, 1H), 6.82 (br t,
1H, J¼7.3 Hz), 6.78e6.74 (m, 2H), 6.51 (d, 2H, J¼7.3 Hz), 6.42 (d, 1H,
J¼8.8 Hz), 5.24 (d, 1H, J¼12.4 Hz), 5.22 (d, 1H, J¼12.4 Hz), 4.96 (d,
1H, J¼10.7 Hz), 4.73 (d, 1H, J¼10.7 Hz), 4.22 (d, 1H, J¼10.7 Hz), 4.12
(q, 1H, J¼6.4 Hz), 4.06 (s, 3H), 4.07e4.03 (m, 1H), 3.94 (s, 3H),
3.90e3.89 (m, 1H), 3.33 (d, 1H, J¼10.7 Hz), 3.23e3.18 (m, 1H), 2.64
(s, 6H), 2.52 (s, 3H), 1.36 (d, 3H, J¼6.4 Hz); 13C NMR (125 MHz,
1. (a) Ravidomycin: Findlay, J. A.; Liu, J.-S.; Radics, L.; Rakhit, S. Can. J. Chem.
1981, 59, 3018; Findlay, J. A.; Liu, J.-S.; Radics, L. Can. J. Chem. 1983, 61, 323;
Sehgal, S. N.; Czerkawski, H.; Kudelski, A.; Pandev, K.; Saucier, R.; Vezina, C.
J. Antibiot. 1983, 36, 355; Narita, T.; Matsumoto, M.; Mogi, K.; Kukita, K.;
Kawahara, R.; Nakashima, T. J. Antibiot. 1989, 42, 347; (b) Deacetylravido-
mycin: Narita, T.; Matsumoto, M.; Mogi, K.; Kukita, K.; Kawahara, R.; Na-
kashima, T. J. Antibiot. 1989, 42, 347; Arai, M.; Tomoda, H.; Matsumoto, A.;
Takahashi, Y.; Woodruff, B. H.; Ishiguro, N.; Kobayashi, S.; Omura, S. J. An-
tibiot. 2001, 54, 554; Arai, M.; Tomoda, H.; Tabata, N.; Ishiguro, N.; Ko-
bayashi, S.; Omura, S. J. Antibiot. 2001, 54, 562; (c) FA35A, FA35B:
Yamashita, N.; Shin-ya, K.; Furihata, K.; Hayakawa, Y.; Seto, H. J. Antibiot.
1998, 51, 1005; (d) Ravidomycin N-oxide, deacetylravidomycin N-oxide:
Narita, T.; Matsumoto, M.; Mogi, K.; Kukita, K.; Kawahara, R.; Nakashima, T.
J. Antibiot. 1989, 42, 347; (e) Deacetylravidomycin M: Arai, M.; Tomoda, H.;
Matsumoto, A.; Takahashi, Y.; Woodruff, B. H.; Ishiguro, N.; Kobayashi, S.;
Omura, S. J. Antibiot. 2001, 54, 554; Arai, M.; Tomoda, H.; Tabata, N.; Ishi-
guro, N.; Kobayashi, S.; Omura, S. J. Antibiot. 2001, 54, 562.
2. (a) Findlay, J. A.; Daljeet, J.-S.; Murray, P. J.; Rej, R. N. Can. J. Chem. 1987, 65, 427;
(b) McKenzie, T. C.; Hassen, W.; Macdonald, S. J. F. Tetrahedron Lett. 1987, 28,
5435; (c) Jung, M. E.; Jung, Y. H. Tetrahedron Lett. 1988, 29, 2517; (d) Patten, A.
D.; Nguyen, N. H.; Danishefsky, S. J. J. Org. Chem. 1988, 53, 1003; (e) Hart, D. J.;
Merriman, G. H. Tetrahedron Lett. 1989, 30, 5903; (f) Deshpande, P. P.; Martin, O.
R. Tetrahedron Lett. 1990, 31, 6313; (g) Parker, K. A.; Coburn, C. A. J. Org. Chem.
1991, 56, 1666; (h) James, C. A.; Snieckus, V. Tetrahedron Lett. 1997, 38, 8149; (i)
Takemura, I.; Imura, K.; Matsumoto, T.; Suzuki, K. Org. Lett. 2004, 6, 2503.
3. Matsumoto, T.; Hosoya, T.; Suzuki, K. J. Am. Chem. Soc. 1992, 114, 3568.
4. Hosoya, T.; Takashiro, E.; Matsumoto, T.; Suzuki, K. J. Am. Chem. Soc. 1994, 116,
1004.
CDCl3)
d 160.6, 157.5, 155.6, 153.1, 142.6, 139.7, 139.2, 138.6, 137.6,
128.6, 128.5, 128.3, 127.8, 127.7, 127.43, 127.42, 127.3, 126.7, 126.4,
125.6, 123.0, 122.6, 122.5, 119.5, 118.5, 114.8, 111.2, 106.1, 83.2, 80.6,
79.3, 76.7, 75.1, 72.2, 71.7, 69.3, 57.2, 56.5, 48.9, 43.8, 21.6, 17.4; IR
(KBr) 1718 (CO) cmꢀ1; HRMS (FAB) m/z calcd for C49H50O8N (MHþ)
780.3473. Found: 780.3505. Anal. Calcd for C49H49NO8: C, 75.46; H,
6.33; N, 1.80. Found: C, 75.19; H, 6.47; N, 1.68.
4.1.14. Deacetylravidomycin M (1). A suspension of compound 20
(30.8 mg, 39.5 mmol), Pd-black in 2 M aqueous HCl solution
(0.4 mL), and MeOH (3.0 mL) was stirred at room temperature
under H2 atmosphere. After stirring for 53 h, reaction mixture was
filtrated through a Celite pad, and satd aqueous NaHCO3 solution
was added. The mixture was extracted with CHCl3 (ꢃ3), and the
combined organic extracts were washed with brine and dried over
MgSO4. After filtration and removal of the solvents in vacuo, the
resultant yellow solids were washed with hexane/EtOAc¼20/1
several times on a funnel. Drying in vacuo afforded 1 (17.8 mg, 88%)
as yellow powder: Rf 0.56 (CHCl3/MeOH/H2O¼6/4/0.3); mp
5. Futagami, S.; Ohashi, Y.; Imura, K.; Hosoya, T.; Ohmori, K.; Matsumoto, T.; Su-
zuki, K. Tetrahedron Lett. 2000, 41, 1063.
6. (a) Ben, A.; Yamauchi, T.; Matsumoto, T.; Suzuki, K. Synlett 2004, 225; (b) See
also: Yamauchi, T.; Watanabe, Y.; Suzuki, K.; Matsumoto, T. Synthesis 2006,
2818.
7. (a) Takemura, I.; Imura, K.; Matsumoto, T.; Suzuki, K. Tetrahedron Lett. 2006, 47,
6673; (b) Takemura, I.; Matsumoto, T.; Suzuki, K. Tetrahedron Lett. 2006, 47,
6677.
215e219 ꢁC (decomp.);
(500 MHz, DMSO-d6)
½
a 2D6
ꢂ
þ47 (c 0.20, CHCl3); 1H NMR
8. Hsu, D. S.; Matsumoto, T.; Suzuki, K. Synlett 2005, 801.
d
9.85 (br s, 1H), 8.50 (1H, s), 7.84 (d, 1H,
9. (a) Hamura, T.; Hosoya, T.; Yamaguchi, H.; Kuriyama, Y.; Tanabe, M.; Miyamoto,
M.; Yasui, Y.; Matsumoto, T.; Suzuki, K. Helv. Chim. Acta 2002, 85, 3589; (b)
Tsujiyama, S. K.; Suzuki, K. Org. Synth. 2007, 84, 272.
10. An azido function has potential reactivity with either n-BuLi and/or benzyne
species. See; (a) Ried, W.; Schoen, M. Chem. Ber. 1965, 98, 3142; (b) Jurgec, M.;
Kovacic, M.; Stanovnik, B.; Tisler, M.; Volk, M. J. Heterocycl. Chem. 1975, 12, 253;
J¼8.4 Hz), 7.79 (br s, 1H), 7.52 (br s, 1H), 6.97 (d, 1H, J¼8.4 Hz), 5.67
(d, 1H, J¼9.0 Hz), 4.36 (br s, 1H), 4.15 (dd, 1H, J¼9.0, 9.0 Hz), 4.12 (s,
3H), 4.11 (s, 3H), 4.01 (q, 1H, J¼6.4 Hz), 3.86e3.85 (m, 1H), 2.62 (br
d, 1H, J¼9.0 Hz), 2.504 (s, 6H), 2.502 (s, 3H), 1.01 (d, 3H, J¼6.4 Hz);