Suggested Reaction 1.2.3.-

Left

3beta-Hydroxy-4beta-methyl-5alpha-cholest-7-ene-4alpha-carbaldehyde
+H2O
+O2

Right

3beta-Hydroxy-4beta-methyl-5alpha-cholest-7-ene-4alpha-carboxylate
+H2O2

[BiSSCat | GREP ]