Methylation of 3 by diazomethane produced in 48% yield 3-acetyl-5,8-dihydroxy-2,6,7-trimethoxy-1,4-
1
naphthoquinone (spinochrome C trimethyl ether, 5), mp 113–115ꢄÑ. Lit. [5]: 126ꢄÑ. Í NMR spectrum (700 MHz, CDCl ,
3
13
ꢅ, ppm): 2.54 (3Í, s, ÑÎÑÍ ), 4.15, 4.090, 4.085 (each 3Í, s, ÎÑÍ ), 12.80, 12.70 (each 1Í, s, 5,8-OH). C NMR spectrum
3
3
(176 MHz, CDCl , ꢅ, ppm): 32.0, 61.7, 61.74, 62.1, 106.5, 111.0, 131.5, 147.3, 148.8, 153.9, 155.6, 158.9, 180.0, 181.9,
3
198.7.
Dimethyl ether 3 was hydrolyzed by heating in conc. HBr at 90°C until the starting material and intermediate monoethers
disappeared (TLC monitoring). The usual work up of the reaction mixture and product separation by PTLC using hexane–
Me CO afforded 1a and 1b. The physicochemical characteristics of the synthesized spinochromes and those isolated from
2
natural sources were identical. Their PMR spectra in CDCl are presented for the first time.
3
3-Acetyl-2,5,6,7,8-pentahydroxy-1,4-naphthoquinone (spinochrome C, 1a). Yield 40%, mp > 250ꢄÑ (dec.).
1
Lit. [5]: 246–248ꢄÑ. Í NMR spectrum (700 MHz, CDCl , ꢅ, ppm): 2.85 (3Í, s, ÑÎÑÍ ), 6.05, 6.53 (each 1Í, br.s, 6,7-ÎÍ),
3
3
13.01, 12.16 (each 1Í, s, 5, 8-ÎÍ), 15.50 (1Í, s, 2-ÎÍ).
2,5,6,7,8-Pentahydroxy-1,4-naphthoquinone (spinochrome D, 1b). Yield 40%, mp > 300ꢄÑ (dec.). Lit. [5]:
1
280–290ꢄÑ (burn). Í NMR spectrum (700 MHz, CDCl , ꢅ, ppm): 6.38, 6.52, 6.85 (each 1Í, br.s, 2, 6, 7-ÎÍ), 6.67 (1Í, s,
3
Í-3), 11.78, 12.04 (each 1Í, s, 5, 8-ÎÍ).
REFERENCES
nd
1.
R. H. Thomson, Naturally Occurring Quinones, 2 Ed., Academic Press, London-New York, 1971, p. 734;
R. E. Moore, H. Singh, and P. J. Scheuer, J. Org. Chem., 31, 3645 (1966); A. Ya. Yakubovskaya, N. D. Pokhilo,
N. P. Mishchenko, and V. F. Anufriev, Izv. Akad. Nauk, Ser. Khim., 788 (2007); N. P. Mischenko, E. A. Vasileva,
and S. A. Fedoreyev, Tetrahedron Lett., 55, 5967 (2014).
2.
L. V. Boguslavskaya, N. G. Khrapova, and O. B. Maksimov, Izv. Akad. Nauk, Ser. Khim., 1471 (1985); A. V. Lebedev,
M. V. Ivanova, N. I. Krasnovid, and E. A. Kolꢂtsova, Vopr. Med. Khim., 45, 123 (1999); R. Kuwahara, H. Hatate,
A. Chikami, H. Murata, and Y. Kijidani, LWT-Food Sci. Tech., 43, 1185 (2010); D. Y. Zhou, L. Qin, B. W. Zhu,
X. D. Wang, H. Tan, J. F. Yang, D. M. Li, X. P. Dong, H. T. Wu, L. M. Sun, X. L. Li, and Y. Murata, Food Chem.,
129, 1591 (2011).
3.
H. Singh, R. E. Moore, C. W. J. Chang, R. T. Ogata, and P. J. Scheuer, Tetrahedron, 24, 2969 (1968); H. Singh,
R. E. Moore, C. W. J. Chang, and P. J. Scheuer, J. Am. Chem. Soc., 87, 4023 (1965).
4.
5.
6.
7.
G. I. Melꢂman, V. A. Denisenko, and V. F. Anufriev, Izv. Akad. Nauk, Ser. Khim., 1734 (2010).
R. E. Moore, H. Singh, C. W. J. Chang, and P. J. Scheuer, Tetrahedron, 23, 3271 (1967).
N. D. Pokhilo, A. Ya. Yakubovskaya, V. F. Anufriev, and D. V. Berdyshev, Zh. Org. Khim., 43, 1177 (2007).
D. V. Berdyshev, V. P. Glazunov, and V. L. Novikov, Izv. Akad. Nauk, Ser. Khim., 400 (2007); V. P. Glazunov,
D. V. Berdyshev, and V. L. Novikov, Izv. Akad. Nauk, Ser. Khim., 2131 (2010).
8.
A. Ya. Yakubovskaya, T. Yu. Kochergina, V. A. Denisenko, D. V. Berdyshev, and V. P. Glazunov, Izv. Akad. Nauk, Ser.
Khim., 294 (2006).
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