Disclosed herein are methods for synthesizing useful intermediates and/or products from 1,2,5,6-hexanetetrol (HTO), which itself can be derived from a sugar. In an aspect, a process is provided for production of THFDCA from 1,2,5,6-hexanetetrol (HTO). The process comprises the steps of (a) ring closing to form a ring compound and (b) oxidizing using a catalyst comprising platinum and bismuth to form an acid mixture. Step (a) may be performed before or after step (b).