However, the difference between nicotine gum and tobacco gum is that tobacco gum is made from finely powdered tobacco mixed with a gum base, rather than freebase nicotine.
But with traditional cigarettes and now e-cigarettes, heat creates a freebase form of nicotine that is more addictive -- or what smokers would call more satisfying.
Finally, deallylation as above, yielded the freebase of oseltamivir, which was converted to the desired oseltamivir phosphate by treatment with phosphoric acid.