Furfural is the precursor e.g. for:
Furfuryl alcohol ("FA"),
Tetrahydrofurfuryl alcohol (THFA),
Furoic acid,
Furfurylamine,
Methylfuran and furan; from furan tetrahydrofuran (THF) is derived, which is the precursor for polytetramethylene ether glycol (PTMEG).