2-Acetoxy-propionaldehyde prepn. from vinyl acetate - with carbon monoxide and hydrogen using rhodium carbonyl cpd. catalysts

2-Acetoxypropionaldehyde (I) is prepd. by reacting vinyl acetate with CO and H2 at raised temp. and press. using carbonyl cpds. of Rh e.g. Rh(CO)2Cl and Rh2(CO)8 as catalyst. Catalyst concn. in reaction mixt. is 0.0001-1 (0.001-0.1) wt.% w.r.t. liq. phase in reaction. Suitable working conditions are 130-180 degrees C, 100-300 bar, mol. ratio CO:H2 2:1 to 1:2, contact times 1-60 min. opt. in presence of solvents, opt. further metal carbonyl cpds. and opt. amine and/or phosphine co-catalysts. (I) can be hydrogenated to 2-acetoxypropanol which can be hydrolysed to 1,2-propanediol, useful as a coolant or as a starting material for prepn. of polyethers and polyester resins. Yields of (I) are higher when using Rh cpd. catalysts in place of Co cpd. catalysts.