By condensation of 1-amino-2-methylpyridinium iodide (I) with isobutyric anhydride (II) by means of K2CO3 at reflux temperature.
The reaction of 6-(4-phenylbutoxy)hexanol methanesulfonate (I) with (R)-phenylglycinol (II) by means of DIEA and NaI in hot acetonitrile gives the secondary amine (III), which is condensed with 2-(benzyloxy)-5-(2-bromoacetyl)benzoic acid methyl ester (IV) by means of DIEA in refluxing 1,2-dimethoxyethane to yield the tertiary amine (V). The enantioselective reduction of (V) with LiBH4 in refluxing dimethoxyethane affords the tetrahydroxy derivative (VI), which is finally debenzylated by hydrogenation with H2 over Pd/C in ethanol to provide the target aminoethanol derivative.