Synthetic approaches to (methaniminomethano)phenanthrenes have been discussed and investigated. Routes to 4-(3,4-dimethoxybenzyl)-6,7-dimethoxy-2- methyl-1,4-dihydro-3(2H)-isoquinolone have been established, but the electrochemical oxidation of this substrate yielded only polymeric material. Similarly a synthesis of 2-formyl-1,2,3,4- tetrahydro-6,7-dimethoxy-4-(3,4-dimethoxybenzyl)isoquinoline was completed and its electrochemical oxidation investigated. A series of 2,3-diphenylpropionamides were synthesised and oxidised using vanadium trifluoride oxide; 2-(2-acetoxy- methyl-3,4-dimethoxyphenyl)-3-(3,4-dimethoxyphenyl)propionamide (I) produced 10,11-dihydro-5,11-(iminomethano>-2,3,7,8-tetramethoxy- 5H-dibenzo [a,d] cyclohepten-12-one (II) and 11-carboxamide-10,11- dihydro-2 ,3,7,8-tetramethoxy-5H-dibenzo [a,d] cycloheptene; the corresponding 2-(2-benzyloxymethy1-3,4-dimethoxyphenyl) derivative of (I) also produced (II); the N-methyl derivative of (I) yielded 2,3,6,7-tetramethoxy-N-methylphenanthrene-9-carboxamide. The structure of the electrochemical product of 4-(3,4-dimethoxybenzyl)6,4-dimethoxyisochroman-3-one (III) was investigated and was shown to be 9,8a-carbonyloxymethano-6,8a,9,10-tetrahydro-2,3,7-trimethoxy-6-oxophenanthrene (IV). The product (IV) was converted into a series of intermediates aimed at the novel 8a,9-(methaniminomethano)phenanthrene ring system.
|Date of Award||1982|