Metaraminol, L-1-(3-hydroxyphenyl)-2-aminopropan-1-ol, is synthesized in two ways. The first way is synthetic, and it is from 3-hydroxypropiophenone. The hydroxyl group is protected by alkylation with benzyl chloride, giving 3-benzyloxypropiophenone. Upon reaction with butyl nitrite, it undergoes nitrosation into the isonitrosoketone, which by reduction using hydrogen over Raney nickel turns into 1-(3-benzyloxyphenyl)-2-aminopropan-1-ol, the protecting benzyl group is removed by reduction using hydrogen over palladium catalyst, to give racemic metaraminol. The desired L-isomer is isolated with the help of (+)-tartaric acid.
The second way is semisynthetic, consisting of fermentation of D-glucose in the presence of 3-acetoxybenzaldehyde, which forms (–)-1-hydroxy-1-(3-hydroxyphenyl)-acetone, the carbonyl group of which is reduced by hydrogen over a palladium catalyst in the presence of ammonia, giving metaraminol.