abstract |
Compounds of the formula (IV) wherein: R2 is methyl or ethyl R3 is hydroxy, C1-C4 alkanoyloxy, aminocarbonyl, methylaminocarbonyl or C1-C2 alkoxycarboxyl; and @@ is an asymmetric carbon atom having the S absolute stereochemical configuration. The compounds are useful intermediates in the preparation of phenethanolamines having pharmaceutical properties. |