In its industrial synthesis, acetylene reacts with two equivalents of formaldehyde to form 1,4-butynediol, also known as but-2-yne-1,4-diol. This type of process is illustrative of what is known as Reppe Chemistry. Hydrogenation of 1,4-butynediol gives 1,4-butanediol.
It can also be manufactured on an industrial scale by the vapour phase hydrogenation of the esters and anhydrides of maleic acid and succinic acid.
Genomatica (a San Diego-based company) has genetically engineered E. coli to devour sugar and construct 1,4-butanediol. They expect to build and begin operating a pilot plant by the end of 2009. CEO Christopher Gann said it takes 32,000 BTU/per pound to make. This is much less than the process listed above, and does not have any by-products.