Methyl 2,4-dihydroxy-3,5,6-trimethylbenzoate

From 4-benzyloxy-3-chloro-6-methoxy-2,5-dimethylbenzoic acid and methyl 2,4-dihydroxy-3,5,6-trimethylbenzoate with TFAA and subsequent debenzylation From 2,4-dibenzyloxy-5-chloro-3,6-dimethylbenzoate and methyl 4-hydroxy-2-methoxy-3,5,6-trimethylbenzoate with TFAA and subsequent debenzylation From 2-benzyloxy-5-chloro-4-methoxy-3,6-dimethylbenzoic acid and methyl 2,4-dihydroxy-3,5,6-trimethylbenzoate with TFAA and subsequent debenzylation... 

The oxidation behavior of 3-oxa-chromanols was mainly studied by means of the 2,4-dimethyl-substituted compound 2,4,5,7,8-pentamethylM /-benzo[ 1,3]dioxin-6-ol (59) applied as mixture of isomers 27a it showed an extreme dependence on the amount of coreacting water present. In aqueous media, 59 was oxidized by one oxidation equivalent to 2,5-dihydroxy-3,4,6-trimethyl-acetophenone (61) via 2-(l-hydroxyethyl)-3,5,6-trimethylbenzo-l,4-quinone (60) that could be isolated at low temperatures (Fig. 6.41). This detour explained why the seemingly quite inert benzyl ether position was oxidized while the labile hydroquinone structure remained intact. Two oxidation equivalents gave directly the corresponding para-quinone 62. Upon oxidation, C-2 of the 3-oxa-chroman system carrying the methyl substituent was always lost in the form of acetaldehyde. 

Methyl-p-orcinolcarboxylic acid, 2,4-Dihydroxy-3,5,6-trimethylbenzoic acid... 

From 3,5-diformyl-2,4-dihydroxy-6-methyl-benzoic acid and methyl 4-hydroxy-2-methoxy-3,5,6-trimethylbenzoate with... 

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