Methoxyethoxymethyl

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

From the intramolecular coupling product, just the two MEM-groups protecting the phenol functions (MEM = 2-methoxyethoxymethyl) have to be removed, in order to obtain the target molecule. 

In the study of Weber et al.,41 a series of proline-derived hydrazones were prepared, and the reactions of the hydrazones with organocerium reagents were examined. It is clear from the table in Scheme 2 24 that the diastereoselectivity of the examined reactions depends on the nature of the side chain. (S )-l-amino-2-(2-methoxyethoxymethyl) pyrrolidine (40) gave the highest selectivity for various nucleophiles. 

Conversion of MEM ethers to esters. 2-Methoxyethoxymethyl (MEM) ethers are converted into carboxylic esters by reaction with an anhydride in the presence of FeCl3 (0.4 equiv.) (equation I). Selective cleavage is possible in the presence of a benzyl ether but not in the presence of a f-butyl ether. Aromatic rings, if present, can undergo acylation. 

These alkylations show a remarkable dependency on the solvent, thus the opposite enantiomer is predominantly obtained when diethyl ether is used instead of tetrahydrofuran during C—C bond formation. Similar results are obtained when the reactions are performed with (S)-l-amino-2-(2-methoxyethoxymethyl)pyrrolidine as the chiral auxiliary8. 

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. 

This cleavage reaction can be used to effect intramolecular homologated cyclization of hydroxy allylsilanes by conversion to the 2-methoxyethoxymethyl (MEM) ether (7, 228-229) followed by cleavage with TiCl4 to the species 6=CH2. 

Treating 3-acetoxy-2-methyl-4/f-pyrido[l,2-sodium hydrogen carbonate in methanol at 60°C for 4 hours, then at ambient temperature for 16 hours, gave 3-hydroxypyridopyrimidine-7-carboxylate 416 (84FES837). The free hydroxyl group of compound 416 was alkylated with an alkyl iodide in dimethylformamide in the presence of potassium carbonate at room temperature or with 2-methoxyethoxymethyl chloride in dichloromethane in the presence of diisopropylethylamine at ambient temperature for 3 hours to give 3-alkoxy derivatives 417. 

MECC micellar electrokinetic capillary chromatography MEM 2-methoxyethoxymethyl (group)... 

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