合成路线1

Two different routes have been described for the preparation of Et-18-OCH3: 1) The methylation of 1,3-benzylideneglycerol (I) with methyl iodide and KOH gives 1,3-benzytidene-2-O-methylglycerol (II), which is hydrolyzed with HCl to 2-O-methylglycerol (III). The condensation of (III) with octadecyl bromide (IV) and KOH in DMSO/THF yields 1-O-octadecyl-2-O-methyl-(rac)-glycerol (V), which by reaction with phosphorodichloric acid 2-bromoethyl ester (VI) and pyridine is converted to 3-octadecyloxy-2-methoxypropyl bromoethyl phosphate (VII). Finally, this compound is converted to Et-18-OCH3 with trimethylamine (VIII) in toluene and treated with silver carbonate to remove traces of bromide. 2) The reaction of 1,2-isopropylidene-sn-glycerol (IX) with benzyl bromide (X) and NaNH2 in benzene gives 1,2-isopropylidene-3-O-benzyl-sn-glycerol (XI), which is hydrolyzed with acetic acid to 3-O-benzyl-sn-glycerol (XII). The etherification of (XII) with (IV) as before or with NaNH2 gives 1-O-octadecyl-3-O-benzyl-sn-glycerol (XIII), which is methylated with methyl iodide and NaNH2 in dioxane to give 1-O-octadecyl-2-O-methyl-3-O-benzyl-sn-glycerol (XIV). Finally, this compound is debenzytaled by hydrogenolysis with H2 over Pd/C in petroleum ether to form (V), an intermediate previously described above.