The present invention relates to systems and methods for producing fuels and fuel precursors from carbohydrates. In an embodiment the invention includes a method of producing 5-hydroxymethylfurfural (HMF), including contacting a saccharide with a metal oxide catalyst at a temperature of greater than about 100 degrees Celsius. In an embodiment the invention includes a method of producing a biofuel including contacting a saccharide with a metal oxide catalyst at a temperature of greater than about 100 degrees Celsius. Other embodiments are also described herein.