synthesis: Synthesis is a purposeful execution of chemical reactions to obtain the desired product. Applies to long and complex natural product syntheses as much as to short one or two-step syntheses. This also covers synthetic problem sets and retrosynthetic analyses. (721 questions as of writing this post)
total-synthesis: Questions involving the synthesis of a natural product or complex drug/molecule pertaining to the individual steps involved or the overall scheme of the reaction (ex. question regarding the individual steps of Woodward's synthesis of vitamin B12). (6 questions as of writing this post)
What is the difference between the two? It looks like total-synthesis is a subset of synthesis but is it required and that it should have its own tag? I get that total-synthesis is only applicable to synthesis of drugs or large macromolecules, however I saw 4 out of 6 questions tagged both synthesis and total-synthesis. So this tag looks a little redundant to me.