preferred_name: 4alpha-hydroxymethyl-4beta-methyl-5alpha-cholest-7-en-3beta-ol + 2 Fe(II)-[cytochrome b5] + O2 + 2 H(+) <=> 3beta-hydroxy-4beta-methyl-5alpha-cholest-7-ene-4alpha-carbaldehyde + 2 Fe(III)-[cytochrome b5] + 2 H2O