Try to do it through oxidation in the presence of catalytic amount of Zn-Bi in water under pressure of O2. In my case, it works very good on a similar compound. After full completion of the reaction, just filter on Celite and concentrate. Should be very clean reaction...Good luck.
---Jing Gao, Dan Liang, Ping Chen, Zhaoyin Hou and Xiaoming Zheng, Oxidation of Glycerol with Oxygen in a Base-free Aqueous Solution over Pt/AC and Pt/MWNTs Catalysts, Catalysis Letters 130, 185-191 (2009) and ref. cited there in (ref.4-16)