Don't you mean butadiene?
You may want to check
this out. Scroll down a little until you see "From ethanol".
What do you need it for? Neoprene may be an easier to make substitute. For neoprene, I believe you can make it by putting vinylacetylene into HCl and letting it sit for a long time. Just google chloroprene (or polychloroprene or neoprene) if you want a to try to find a step by step instruction.