3- Methoxyethoxymethyl ethers

A 2-methoxyethoxymethyl ether was used to protect one phenol group during a total synthesis of gibberellic acid. 

Methoxyethoxymethyl ethers, MEM-ethers, are formed by reaction of an alcohol (1 mol) with 2-methoxyethoxymethyl chloride (1.5 mol, MEM-chloride) in dichloromethane solution (10 ml/g of MEM-chloride) at room temperature in the presence of ethyldiisopropylamine (1.5 mol)80 this literature report also notes other preparative procedures. 

A 2-methoxyethoxymethyl ether (MEMOR) is normally prepared under non-acidic conditions in methylene chloride solution or under basic conditions. The MEM ether group can be removed in excellent yield with trifluoroacetic acid (TEA) in dichloromethane (1 1). The MEM group can also be removed by treatment with zinc bromide (ZnBr2), titanium chloride (TiCU) or bromocatechol borane. When MEM-protected diols are treated with zinc bromide (ZnBr2) in ethyl acetate, 1,3-dioxane is formed and a mechanism of this reaction is given in Scheme 1.23. 

In an attempt to metalate a MEM-protected phenol with BuLi, the methoxy group was eliminated forming the vinyloxymethyl ether. This was attributed to intramolecular proton abstraction. A 2-methoxyethoxymethyl ether was used to protect one phenol group during a total synthesis of gibberellic acid. ... 

Benzyl ethers. A soln. of -octyl tetrahydropyran-2-yl ether in toluene treated with (methylthio)tributylstannane and BF3-etherate at 0°, stirred for 7 h, solvent replaced by DMF, benzyl iodide, CsF and 3A molecular sieves added, and the mixture stirred at room temp, for 20 h - benzyl octyl ether. Y 78%. F.e. ircl. 2-methoxyethoxymethyl ethers, acoxy compds., and tosylates, also oxo compds. with pyridinium chlorochro-mate, s. T. Sato et al.. Tetrahedron Letters 30, 1665-8 (1989) acoxy compds., direct method with MeCOCl (cf. 27,241), s. T. Bakos, I. Vincze, Synth. Commun. 19, 523-8 (1989). 

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