Fluoride salts-alcohols-alumina as reagents for nucleophilic substitution of chlorine atoms for alkoxy groups in 2,3-dichlorosubstituted juglones, naphthazarines, and quinizarines
作者:Victor Ph. Anufriev、Vyacheslav L. Novikov
DOI:10.1016/0040-4039(95)00295-n
日期:1995.4
Direct displacement of chlorine atoms by alkoxy groups in 2,3-dichlorosubstituted juglones (5-hydroxy-1,4-naphthoquinones), naphthazarines (5,8-dihydroxy-1,4-naphthoquinones), and quinizarines (1,4-dihydroxy-9,10-anthraquinones) is generally ineffective, however high yields are obtained when methanol or cellosolves activated by fluoride anion are used as nucleophiles and the reaction goes in the presence
Naphthoquinoid pigments of sea urchins. Trimethyl orthoacetate as an effective reagent for O-methylation of β-OH groups of spinazarin, spinochromes D and E, and echinochrome A
作者:O. P. Shestak、N. N. Balaneva、V. L. Novikov、V. P. Glazunov
DOI:10.1007/s11172-024-4328-1
日期:2024.7
preparative amounts of 6-monomethyl ethers of spinochrome D and echinochrome A, 7-monomethyl ether (namakochrome) and 6,7-dimethyl ether of spinochrome E, which are difficult to prepare by other methods, and to carry out complete O-methylation of all discussed pigments. Among the known O-methylating agents, TMOA is most suitable for the preparative syntheses of methylethers of polyhydroxynaphthazarins.
原乙酸三甲酯 (MeC(OMe) 3 , TMOA) 是一种方便的试剂,可选择性和完全 O-甲基化海胆色素的 β-OH 基团,例如菠那素、旋色素 D 和 E 以及棘色素 A。与TMOA的化合物可以提供制备量的刺色素D和棘色素A的6-单甲醚、刺色素E的7-单甲醚(namakochrome)和刺色素E的6,7-二甲醚,这些是通过其他方法难以制备的,并且对所有讨论的颜料进行完全 O-甲基化。在已知的O-甲基化剂中,TMOA最适合用于制备聚羟基萘甲醚的制备合成。
The Synthesis of Spinochromes A, C, D, and E
作者:Ishwar Singh、Richard E. Moore、Clifford W. J. Chang、Paul J. Scheuer