L-Allyl-2, 4-dimethoxybenzene

Eugenol methyl ether (4-allyl-l,2-dimethoxybenzene) [93-15-2] M 178.2, m -4 , b 127-129 /llmm, 146 /30mm, 154.7 /760mm, dj 1.0354, n 11.53411. Recrystd from hexane at low temp and redistd (preferably in vacuo). [Hillmer and Schoming Z Phys Chem [A] 167 407 1934 Briner and Fliszdr Helv Chim Acta 42 2063 1959.]... 

SCHEME 14.4 Synthesis of a lipid IV analogue by Khane and coworkers. ADMB, 4-allyl-l,2-dimethoxybenzene DTBMP, 2,6-di-ferf-butyl-4-methylpyridine HATU, 0-(7-azabenzotriazole-l-yl)-iV,iV,iV, iV -tetramethyluronium hexafluorophosphate mCPBA, m-chloroperoxybenzoic acid TCP, tetrachlorophthaloyl Teoc, 2-trimethylsilylethoxycarbonyl. 

ALLYL-l,2-DIMETHOXYBENZENE see AGE250 ALLYLDIOXYBENZENE METHYLENE ETHER see SADOOO... 

An important example is methyleugenol (4-Allyl-l,2-dimethoxybenzene). In 1999, methyleugenol was evaluated by the CEFS of the council of Europe. The conclusions of this Committee were as follows ... 

Related with the previous synthesis, an FC aminoalkylation through a tosyliminium ion allowed the total synthesis of ( )-schefferine (Scheme 2.6) [7], which is a phenolic alkaloid isolated from Schefferomitra subaequalis, a liana climber found on rain forest trees. The known amidal 41 was treated at -78°C with 4-allyl-l,2-dimethoxybenzene (42) and BF Et O to regioselectively give 43 in 88% yield. The allylic chain of the aromatic ring was then modified to furnish alcohol 44, which after deprotection of the tosylamide was cyclized via a Mitsunobu reaction to give ( )-schefferine (46). 

Council of Europe, Opinion of the Scientific Committee on Food on Methy-leugenol (4-Allyl-l,2-dimethoxybenzene), European Commission Health and Consumer Protection Directorate-General, Brussel, Belgium, 2001. Available at http //europa. eu.int/comm/food/fs/scf/ index en.html. 

The Bz-hydroxylated 2,3-dihydrobenzofuran derivatives required for the synthesis of several natural substances have been obtained by this method 4-allyl-l,3-dimethoxybenzene gives (HBr/HOAc with de-methylation) 6-hydroxy-2-methyl-2,3-dihydrobenzofuran.427 2-Allyl-4-methoxyphenol and 2-allyl-3,5-dimethoxyphenoI lead, respectively, to 5-methoxy-2-methyl-2,3-dihydrobenzofuran and 4,6-dimethoxy-2-methyl-2,3-dihydrobenzofuran (without demethylation). 

SYNS l-ALLYL-3,4-DIMETHOXYBENZENE 4-ALLYLVERATROLE l,2-DIMETHOXY-4-ALLYL-BENZENE l-(3,4-DIMETHOXYPHENYL)-2-PROPENE ENT 21,040 1,3,4-EUGENOL METHYL ETHER EL GENYL METHYL ETHER FEMA No. 2475 METHYL EUGENOL (FCC) VERATROLE METHYL ETHER... 

The stereostructure of isoasatone (6.1a) was established through the X-ray crystallographic analysis of its LiAlHt-reduction product, di-hydroxyisoasatone (131), and rationalizes the fact that the compound yields a mixture of 5-allyl-2-hydroxy-l,3-dimethoxybenzene (46%) and 6,6 -diallyl-3,3 -dihydroxy-2,4,2, 4 -tetramethoxybiphenyl (12%) upon reduction with zinc in acetic acid (146). Since asatone is cleaved by this reagent into the same aromatic compounds and can be converted photo-chemically into isoasatone (see Section XIV, Chart 26, 5.1a- 6.1a), its previously proposed structure (42) must be revised to 5.1a (147). 

Foods may contain a number of alkyl aryl ethers that are components of essential oils of different spices as well as secondary substances. These ethers are most often derived from anisole (methoxybenzene, 8-33) or veratrole (1,2-dimethoxybenzene, 8-33), which are substituted by a prop-l-en-yl or l-prop-2-en-l-yl (allyl) group at the C-4 position of the benzene ring. An important ether is estragole (also known as 4-aUylanisole or methyl chavicol, 8-33), which is the main component (over 80%) of basil essential oil (see Table 8.32, later) and tarragon (dragon s wort) essential oil... 

A 31.0 g sample of l-allyloxy-2,4-dimethoxybenzene was gently heated with a soft flame until the internal temperature reached 215 °C. An exothermic reaction took place, with the temperature rising to 270 °C. The residue left in the flask was largely 2-allyl-4,6-dimethoxy phenol, that contained perhaps 10% of 2,4-dimethoxyphenol which resulted from the pyrolytic loss of the allyl group. This mixture was methylated without further purification. 

The above crude 3,4-dimethoxyphenol was dissolved in 200 mL EtOH, and treated with a solution of 38.1 g KOH in 300 mL hot EtOH. The clear solution of the potassium salt was a deep red color, and was promptly treated with 94.3 g allyl bromide, at a rate commensurate with the exothermic reaction. The mixture was held at reflux for 2 h. This was then added to 1 L H20 and extracted with 5x100 mL Et20. The extracts were pooled, and removal of the solvent under vacuum gave a residue of 98 g of a black oil. This was distilled at 104-108 °C at 0.7-1.0 mm/Hg to give 59.3 g 1-allyloxy-3,4-dimethoxybenzene as a pale yellow oil with a greenish cast. 

Methylnaphthalene Ethyl cinnamate l-Allyl-3,4-dimethoxybenzene Butyl benzoate Acenaphthene... 

Butoxyethoxy)ethyl acetate 1 -Methylnaphthalene 2-Methylnaphthalene l-Allyl-3,4-dimethoxybenzene... 

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