3.4- Dimethoxy-6-methylphenol

Dimethoxy-6-methylphenol and furan in acetic anhydride contaning tetra-n-butylammonium fluoroborate by electrolysis at 160-220mV with a current of 0.27mA/cm2 until 2F/mol. had been consumed gave the furylcyclohexadienone in the moderate yield of 32% (ref.31). 

Creosol (2-methoxy-4-methylphenol) (I), for instance, yields 14.5% methanol and 15% carbon dioxide on a mole basis. Besides these degradation products, up to 60% of the crystalline o,o -dihydroxybiphenyl derivative (6,6 -bicreosol—i.e., 2,2 -dihydroxy-3,3 -dimethoxy-5,5 -dimethylbi-phenyl-1,1 ) (II) and small amounts of a higher molecular humic-like compound could be isolated. 

Dimethoxy-4-hydroxycinnamaldehyde Phenol, 2,6-dimethoxy Eugenol 2-Methoxy-6-methylphenol Vanillin Phenol, 2-methoxy-4-(l-propenyl) S additional peaks 3, S-Dimethoxy-4-hydroxycinnamaldehyde... 

On constant current electrolysis (0.27 mAcm +180-600 mV V5. SCE) in AC2O containing ethyl vinyl ether, 4,5-dimethoxy-2-methylphenol (108) was converted to two cyclohexa-2,4-dienones 109 and 110 and cyclohexa-2,5-dienone 111, in 29, 18 and 8% yields, respectively (Scheme 20). The product 110 is formed by nucleophilic substitution at the C-6 position followed by acetal formation with EtOH molecule generated initially from the ethyl vinyl ether while the C-4 position is attacked by ethyl vinyl ether to yield 111. 

SCHEME 20. Anodic oxidation of 4,5-dimethoxy-2-methylphenol in the presence of ethyl vinyl ether... 

Dimethoxy-2-methylphenol (108) which was electrolyzed in 2 3 AciO-AcOH including frawi-l,2-dimethoxy-4-propenylbenzene (140) underwent cationic [5 4- 2] cycloaddition affording in 80% yield the corresponding bicyclo[3.2.1]oct-3-en-2,8-dione 154, which was readily converted to hehninthosporal (155), a toxic sesquiterpene (Scheme 30) . 

Dimethoxy-2-methylphenol (108) was oxidized with DDQ in MeOH at 0°C to afford in 63% yield 2-methyl-4,4,5-trimethoxycyclohexa-2,5-dienone (518), which reacted with 1,2-dimethylcyclopentene (519) in MeN02-CH2Cl2 containing stannic chloride to yield a mixture of two adducts. This mixture was reduced directly with NaBHj in MeOH to give a separable mixture of 520 and 521 in 10% overall yield. The former was smoothly converted to the target molecule 517 (Scheme 98). 

XXXVII). Further reduction (Clemmensen) yielded 3,4,4 -trimethoxy-6,6 -diethyl-l,l -dimethyl-2,3 -diphenyl ether (XXXVIII), which proved to be identical with a synthetic product obtained by the Ullmann condensation of 1,2-dimethoxy-4-ethyl-5-methyl-6-bromobenzene and the sodium salt of 2-methoxy-4-ethyl-5-methylphenol. Oxyacanthine therefore is composed of two benzyltetrahydroisoquinoline rings linked by two oxygen bridges and must have the formula XXVI or XXXI. 

Dimethoxytoluene allowed to react with a Vilsmeier complex prepared in situ from dry dimethylformamide and POCL -> 2,4-dimethoxy-3-methylbenz-aldehyde (Y 83%) refluxed 24 hrs. with m-diloroperoxybenzoic acid in dry methylene chloride, and the intermediate formoxy compd. hydrolyzed under Ng with aq.-alc. KOH (cf. Synth. Meth. 17, 338) -> 2,4-dimethoxy-3-methylphenol (Y 96%). F. e. s. I. M. Godfrey, M. V. Sargent, and J. A. Elix, Soc. Perkin I 1974,1353. 

Chloro-3,5-dimethoxy toluene, in C-30058 2-(3-Chloro-1,3-dimethylcyclohexyl)-5-methylphenol, C-10074 2-(4-Chloro-1,3-dimethylcyclohexyl)-5-methylphenol, C-10075 4-Chloro-3,23-dioxoergosta-4,24(28)-dien-21-oic acid, in C-10082... 

The following aromatic compounds have been detected by GLC in small amounts in Evernia prunastri (L.) Ach. benzene, toluene, isopropylbenzene, m-ethyltoluene, mesitylene, 1,2,3-trimethylbenzene, isobutylbenzene, bro-mobenzene, l,2-dimethyl-3-ethylbenzene, 1-chloro-2,4-dimethoxy-6-methylbenzene, a,p-dimethylstyrene, naphthalene, bis-(p-tolyl)-1,2-ethane, phenol, 2-chloro-3-methoxy-5-methylphenol, phthalic acid and N,N-dimethyl-p-toluenesulfonamide (Gavin and Tabacchi 1975), and a,a-dimethylstyrene,... 

Also obtained on deacylation of 2,4-diacetyl-3,5-dimethoxy-6-methylphenol acetate with 10% hydrochloric acid in ethanol [3042]. 

Preparation by reaction of acetyl chloride on 3,5-dimethoxy-4-methylphenol with aluminium chloride in ethyl ether first at 0°, then at r.t. [2877,3285,3286], (40%) [2877]. 

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