Always check for orthogonal reactivity . Ensure that the reagent you use in Step 3 doesn't destroy the functional group you carefully installed in Step 1. This is where protecting groups (like TBDMS or Acetals) become essential tools in your mental toolbox.
In acidic media, avoid drawing strong bases (like OH−cap O cap H raised to the negative power ). In basic media, avoid drawing strong acids ( H3O+cap H sub 3 cap O raised to the positive power advanced organic chemistry practice problems