4-Hydroxy-3-methoxybenzyl alcohol,

Electrophiles other than protons were indeed shown to react with lignin model compounds at the 2- and 6-positions in acidic media Kratzl and Wagner investigated the reaction of paraphenolic benzyl alcohols in alkaline and acidic solutions (10). When 4-hydroxy-3-methoxybenzyl alcohol 4 was reacted with the 4-alkyl substituted phenol 5 under alkaline conditions, the expected ortho linked product (6) was isolated. However, under acidic conditions the methylene linkage formed meta to the phenolic hydroxy group (Fig. 2). 

The details of the reaction conditions used in this study have been described elsewhere (Dershem, S. M., et al., Holzforschung Fisher, T. H., et al., J. Org. CAem., in press). To test the importance of a p-hydroxyl substituent, the kinetics of oxidation of three benzyl alcohols p-hydroxybenzyl alcohol, (1), m-hydroxybenzyl alcohol, (2), and 4-hydroxy-3-methoxybenzyl alcohol, (3), were examined under alkaline nitrobenzene oxidation conditions. Some l-(4-hydroxyphenyl)-2-(4 -substituted phenyl)ethanols, (4), were synthesized as / -l lignin model compounds and subjected to alkaline nitrobenzene oxidation at 120 °C to study substituent effects. For controls, some of these compounds were reacted with or without nitrobenzene, alkaline catalyst, or water. In an effort to determine the effects of substituents on the oxidative-cleavage reaction of 4-hydroxystilbenes (5), a series of competitive rate experiments using both nitrobenzene and copper(II) as the oxidants in 2N NaOH was performed (Dershem, S. M., et al., Holzforschung, in press). 

An aryl-alcohol oxidase produced optimally under carbon limitation from Bjerkandera adusta oxidized a number of benzyl alcohols including 4-methoxybenzyl alcohol, 3,4-dimethoxybenzyl alcohol (veratryl alcohol), and 4-hydroxy-3-methoxybenzyl alcohol, with the production of H202 from 02 monosaccharides were not oxidized (Muheim et al. 1990). An aryl-alcohol oxidase from Pleurotus eryngii is a flavoprotein with range of substrates comparable to that from B. adusta (Guillen et al. 1992). 

This is a solvolysis reaction that proceeds in two steps. The first step involved protonation of the hydroxy group of p-methoxybenzyl alcohol. Once protonated, a bromide ion displaces water, generating the illustrated product. The reaction shown below demonstrates this reaction through an Sk2 mechanism however, this reaction can also be represented through an S -l reaction involving initial... 

Reduction of l-(4-methylphenyl)ethanol affords a 4 1 mixture of the 2, 5 -dihydro derivative with 4-ethyltoluene," showing again the influence of an electron-releasing substituent in the para position. The result with 4-methoxybenzyl alcohol appears to be completely general. Benzylic hydroxy groups may also be preserved when the proximal aryl ring is hydroxylated, as in the formation of (207 Scheme 42) and in the reduction outlined in Scheme 45." ... 

Facile and selective reactions with 3-hydroxy-2-butanone, 4-methoxybenzyl alcohol, and 3-ferf-butoxycyclohexanol were observed without any side reactions and yielded corresponding alkoxy polysiloxanes in excellent yields (Entries 1,4, and 5 Table 3.3). Amino substituted polysiloxanes are desirable products due to their utility in various technological applications, but salt-free direct methods of their preparation are quite rare. To our surprise, the Pd-nanocluster alcoholysis reaction of PMHS with 2-(2-aminoethylamino)ethanol provided corresponding amino substituted polysiloxane (Entry 2, Table 3.3) in fair yields without undergoing degradation or rearrangement reactions. However, it should be pointed out that double the amount of solvent was used for alcoholysis of amine-functionalized alcohols, since the viscosity of the reaction mixture increased rapidly (as compared to nonamine functionalized alcohols) as reaction progressed. Similarly,... 

Me ether [73731-89-2]. 2J,6 Tribromo-4-hydroxy-5-methoxybenzyl alcohol C H7Br303 M 390.853... 

Me ether [4383-06-6]. 3-Hydroxy-4-methoxybenzenemethanol, 9CI. 3-Hydroxy-4-methoxybenzyl alcohol, SCI. Isovanillyl alcohol Cryst. (toluene). Mp 131-132 . 

On the other hand, the combined use of ZrCU and Nal can be applied for conversion of hydroxy group into iodide as shown in Equation 81 [86]. In refluxing acetonitrile, methoxybenzyl alcohol was smoothly changed into the corresponding iodide. Benzyl alcohol, primary, secondary, ally lie, and adamantyl alcohols were also converted into the corresponding iodides under the same conditions. 

Six protective groups for alcohols, which may be removed successively and selectively, have been listed by E.J. Corey (1972B). A hypothetical hexahydroxy compound with hydroxy groups 1 to 6 protected as (1) acetate, (2) 2,2,2-trichloroethyl carbonate, (3) benzyl ether, (4) dimethyl-t-butylsilyl ether, (5) 2-tetrahydropyranyl ether, and (6) methyl ether may be unmasked in that order by the reagents (1) KjCO, or NH, in CHjOH, (2) Zn in CHjOH or AcOH, (3) over Pd, (4) F", (5) wet acetic acid, and (6) BBrj. The groups may also be exposed to the same reagents in the order A 5, 2, 1, 3, 6. The (4-methoxyphenyl)methyl group (=MPM = p-methoxybenzyl, PMB) can be oxidized to a benzaldehyde derivative and thereby be removed at room temperature under neutral conditions (Y- Oikawa, 1982 R. Johansson, 1984 T. Fukuyama, 1985). 

Dimethoxybenzyl esters prepared from the acid chloride and the benzyl alcohol are readily cleaved oxidatively by DDQ (CH2CI2, H2O, rt, 18 h, 90-95% yield). A 4-methoxybenzyl ester was found not to be cleaved by DDQ. The authors have also explored the oxidative cleavage (ceric ammonium nitrate, CH3CN, H2O, 0°, 4 h, 65-97% yield) of a variety of 4-hydroxy- and 4-amino-substituted phenolic esters. ... 

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