Directed metalation of N,N-diethylbenzamides. Silylated benzamides for the synthesis of naturally occurring peri-methylanthraquinones and peri-methyl polycyclic aromatic hydrocarbons
- Univ. of Waterloo, Ontario (Canada)
Efficient methodologies based on directed ortho metalation, fluoride-induced carbodesilylation, and metal-halogen exchange processes (Scheme I) are reported for the synthesis of peri-methyl-substituted anthraquinone natural products 5 and polycyclic aromatic hydrocarbons 6, 7. Benzamide 8 (Scheme II) is converted in a one-pot sequence into the disilylated derivative 10, which upon metalation, condensation with 3,5-dimethoxybenzaldehyde, CsF desilylation, and TsOH cyclization leads to the key phthalide 11. Compound 11 is transformed into deoxyerythrolaccin tris(methyl ether) 5c, which has been previously converted into the natural product 5a. For the synthesis of erythrolaccin tetrakis(methyl ether) 5d, the silyl and bromo benzamides 14 and 15 (Scheme III) are condensed with 3,5-dimethoxybenzaldehyde by CsF-induced carbodesilylation and metal-halogen exchange expedients, respectively, to give the phthalide 16, which is transformed into the target anthraquinone 55d by methods identical with those used in 5c. Along similar lines, the synthesis of 11-methyl-7,12-benz(a)anthraquinone (6a, Scheme IV), 8-methyl-7,12-benz(a)anthraquinone (6b), and 10-methyl-9,14-dibenz(a,c)anthraquinone (7) is described.
- OSTI ID:
- 7071002
- Journal Information:
- Journal of Organic Chemistry; (USA), Journal Name: Journal of Organic Chemistry; (USA) Vol. 54:18; ISSN 0022-3263; ISSN JOCEA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Genetic differences in metabolism of polycyclic aromatic carcinogens and aromatic amines by mouse liver microsomes. Detection by DNA binding of metabolites and by mutagenicity in histidine-dependent Salmonella typhimurium in vitro
Mouse skin tumor-initiating activity of 5-, 7-, and 12-methyl- and fluorine-substituted benz(a)anthracenes
Related Subjects
400201* -- Chemical & Physicochemical Properties
550000 -- Biomedical Sciences
Basic Studies
59 BASIC BIOLOGICAL SCIENCES
ANTHRAQUINONES
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
AROMATICS
CARCINOGENS
DATA
DATA ANALYSIS
DRUGS
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
MEASURING INSTRUMENTS
MEASURING METHODS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
POLYCYCLIC AROMATIC HYDROCARBONS
QUINONES
SYNTHESIS