An integrated approach to the synthesis of contiguously substituted xanthopurpurins, pachybasins and purpurins.
摘要:
Alkylation, hydroxyalkylation and acylation of 3-methyl-, 3-methoxy- and 3,4-dimethoxycrotonates can be induced to occur exclusively in the alpha-Position. Conversion of the products to dienes then provides, through cycloaddition, a wide variety of substitution patterns. This approach is illustrated by simplified syntheses of a number of naturally occurring quinones and confirms the structures proposed for vismiaquinone C, 7-geranylemodin, cinnalutein, 4,5-dihydroxydigitolutein, 2-hydroxyislandicin 1-methyl ether and calyculatone 1-methyl ether.
An integrated approach to the synthesis of contiguously substituted xanthopurpurins, pachybasins and purpurins.
作者:Brigitte Caron、Paul Brassard
DOI:10.1016/s0040-4020(01)80322-7
日期:1993.1
Alkylation, hydroxyalkylation and acylation of 3-methyl-, 3-methoxy- and 3,4-dimethoxycrotonates can be induced to occur exclusively in the alpha-Position. Conversion of the products to dienes then provides, through cycloaddition, a wide variety of substitution patterns. This approach is illustrated by simplified syntheses of a number of naturally occurring quinones and confirms the structures proposed for vismiaquinone C, 7-geranylemodin, cinnalutein, 4,5-dihydroxydigitolutein, 2-hydroxyislandicin 1-methyl ether and calyculatone 1-methyl ether.
Two anthraquinones from Ventilago calyculata
作者:B.Kesava Rao、T. Hanumaiah、J.U.M. Rao、K.V.J. Rao、Ronald H. Thomson
DOI:10.1016/s0031-9422(00)84996-1
日期:1984.8
Abstract Two new anthraquinones have been isolated from the rootbark of ventilago calyculata and their structures shown to be 2,4,8-trihydroxy-1-methoxy-3-methylanthraquinone and 2,4,8-trihydroxy-1,6-dimethoxy-3-methyl-anthraquinone.