2-Benzyloxy-4-methoxy-6-methylbenzoic

From 2-benzyloxy-4-methoxy-6-methylbenzoic acid and 2- -heptyl-4,6-dihydroxybenzoate with TFAA and subsequent debenzylation... 

As a typical example of tridepside synthesis, the preparation of 5-0-methylhiascic acid (227) is depicted in Scheme 35 122). Persulfate oxidation of ethyl 4-benzyloxy-2-hydroxy-6-methylbenzoate (273) in potassium hydroxide solution gave the corresponding 5-hydroxy derivative (274) from which 2,4-dibenzyloxy-5-methoxy-6-methylbenzoic acid (275) was prepared. Condensation of this acid with benzyl lecanorate (276) gave the... 

Preparation by hydrogenolysis of 2, 2 -bis (benzyloxy)-3,5,5 -trichloro-4, 4 -dimethoxy-6,6 -dimethylbenzo-phenone (SM) with hydrogen in the presence of 10% Pd/C in ethyl acetate containing concentrated hydrochloric acid (5 drops) (>90%) [1339]. SM was obtained by Friedel-Crafts acylation of 5-(benzyloxy)-2-chloro-3-methoxy-toluene with 2-(benzyloxy)-3,5-dichloro-4-methoxy-6-methylbenzoic acid in the presence of trifluoroacetic anhydride in refluxing ethylene dichloride for 5 h (28%). 

Preparation by hydrogenolysis of 2,2, 4 -tris-(benzyloxy)-3,5-dibromo-6-methoxy-4,6 -dimethyl-benzophenone (SM) in ethanol/trifluoroacetic acid mixture in the presence of 10% Pd/C at atmospheric pressure (quantitative yield). SM was obtained by condensation of 0-benzyl-0-methyl-3,5-dibromo-y-orsellinic acid— 2-(benzyloxy)-3,5-dibromo-6-methoxy-4-methylbenzoic acid—with orcinol dibenzyl ether in the presence of nifluoroacetic anhydride/trifluoroacetic acid mixture under nihogen in refluxing chloroform for 6.25 h [1376]. m.p. and Spectra (NA). 

Xanthoparmelia duplicata From 4-benzyloxy-2-methoxy-3,6-di-methylbenzoic acid and benzyl 2,4-dihydroxy-3,6-dimethylbenzoate with TFAA and subsequent ddienzylation (199)... 

By condensation of 2,4-dibenzyloxy-6-methylbenzoic acid and benzyl 4-benzyloxy-3-(2, 4 -dihydroxy-6 -methyl-benzoyloxy)-6-hydroxy-2-methylbenzoate with TFAA and subsequent debenzylation From 4-benzyloxy-2-hydroxy-6-/i-pentylbenzoic acid and olivetol with DCCD and subsequent debenzylation From 2-hydroxy-4-methoxy-6-n-propyl-benzoic acid and divarol with DCCD From 2-hydroxy-4-methoxy-6-n-propyl-henzoic acid and 3-methoxy-5-n-propylphenol with DCCD From 4-benzyloxy-2-hydroxy-6-n-pentyl-benzoic acid and 3-methoxy-5-n-propylphenol with DCCD and subsequent debenzylation... 

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