Interestingly, when submitting CA to the best set of conditions (110 °C, 50 bar CO:H2) in acetonitrile, similar conversion of CA is obtained but with reversed selectivity: MeSA is obtained with 53% yield, and GA is obtained with 25% yield (100 % selectivity towards anhydrides, 68:32 MeSA:GA ratio). As it seems unlikely for double-bond isomerization to be more disfavoured in MeCN compared to acetone, this might indicate that the Lewis acid species formed during disproportionation of the cobalt precursor is different in acetone and MeCN. (5 mol%) in acetone (2 mL), heated for the indicated duration under pressure of gas mix. MA and CA conversions and MeSA and GA yields measured by GC-MS analysis; selectivity calculated as the ratio between yield and conversion. n.d.: not determined.