Processes are described for making biobased isoprene, wherein a biobased isobutene prepared from acetic acid in the presence of a catalyst is combined with a formaldehyde source to form a reaction mixture, and the reaction mixture is reacted to yield biobased isoprene. In certain embodiments, methyl-tert-butyl ether prepared by reacting the same biobased isobutene with methanol serves as a formaldehyde source, being oxidatively cracked to produce formaldehyde as well as isobutene for being converted to the biobased isoprene.