In the classical geometrical isomerism nomenclature of oximes, the stereochemical descriptors 'Syn' — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

For unsymmetrical ketoximes ($R-C(R')=N-OH$), where two different alkyl groups are attached to the central carbon, the IUPAC convention assigns 'syn' and 'anti' relative to the alphabetically preferred alkyl group. If the $-OH$ group is on the same side as the alphabetically prior group, it is named 'syn'.