an integrated method for production of liquid transportation fuels , fuel additives , or chemicals in a biorefinery by the conversion of cellulosic materials is disclosed herein . the method is based on converting a source of c6 sugar such as cellulosic materials and sugars into a mixture of hydrotreated compounds . the biorefinery operates in a unique parallel - processing mode , wherein the initial biomass feedstocks are disassembled to provide substrates for parallel branches whose products may be reassembled in either a condensation step or a mixed hydrotreating step or a final fuel - blending step . the cellulosic materials can be converted to levulinate intermediates that condense with intermediates derived from other processes to produce fuels with the appropriate range of sizes in the target molecular composition , thus generating desirable combustion and physical properties . this method also makes use of methyltetrahydrofuran and other low carbon by - products that are separated for use as amphiphilic solvents . in an embodiment , the method produces cyclic ethers via mild hydrotreating of the condensation products , or long - chain keto ester , useful for plasticizers , by condensing a portion of the levulinate with a reagent containing an unsaturated group . in another embodiment , the method produces a ketal by converting a portion of the condensation product in an acid - catalyzed reaction with a diol .