TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The step (a) is conducted at a temperature of 100-300 degrees C, preferably 150-200 degrees C and at a dynamic temperature range for residence time of the reaction consisting of 1 minutes to 24 hours, 1 minutes to 20 hours, 1 minutes to 12 hours, 1 minutes to 6 hours, 1 minutes to 3 hours, 1 minutes to 2 hours, 1 minutes to 1 hour and 1 minutes to 30 min. The dynamic temperature range ramps from a first temperature to a second temperature that is higher than the first temperature, and changes from a first temperature to a second temperature in a non-linear fashion and/or a discontinuous fashion. In step (a), the biomass or a biomass-derived reactant comprises water-insoluble glucose-containing polymers or oligomers, and/or water-insoluble xylose-containing polymers or oligomers. The water-insoluble glucose-containing polymers or oligomers, and/or water-insoluble xylose-containing polymers or oligomers, if present in biomass or a biomass-derived reactant, are converted to water-soluble glucose-containing oligomers, glucose monomers, water-soluble xylose-containing oligomers and/or xylose monomers. Preferred Components: The organic solvent: is miscible with water; dissolves 2-40 wt.% water; is gamma -valerolactone; and is present at a mass ratio with water consisting of 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5, 97:3, 98:2 and 99:1. The acid catalyst is homogeneous acid catalyst or heterogeneous acid catalyst, and is a mineral acid or an organic acid, and a solid acid catalyst consisting of solid Bronsted acid catalysts and/or solid Lewis acid catalysts. If the acid catalyst is homogeneous acid catalyst, the catalyst is present in a concentration of less than 100 mM based on volume of the solvent system. If the acid catalyst is heterogeneous acid catalyst, the catalyst is present in a concentration of less than 1 wt.% based on weight of the solvent system. The solid acid catalyst is: a heteropolyacid; an amorphous or mesoporous silica that is unfunctionalized or functionalized with an acidic modifier; and a zeolite. The solute is a water-soluble, inorganic salt. The salt is added to the product mixture in a saturating amount, and is sodium chloride. EXAMPLE - No suitable example given.