1-Butanol → (2R,3S,4R,5R)-2,3,4,5,6-pentahydroxyhexanal

A maleic acid ester of an APG was prepared as follows. To a 1 L erlenmeyer flask, containing a magnetic stir bar, was added 185.1 g anhydrous n-butanol (Aldrich, 99.8%), 36.1 g n-octanol (Aldrich, 99+%), and 2.0 g deionized water. To the stirred mixture, 0.184 g (100 mL) of concentrated sulfuric acid (J. T. Baker, 96.6%) was added using a 1 mL glass syringe. This mixture was added to a 500 mL three necked round bottom flask containing 50.0 g of anhydrous α-D-glucose (Aldrich, 96%) and a concave magnetic stir bar. The flask was fitted with a thermocouple probe, a dry air intake, and a 25 mL Barrett receiver on which two glass condensers were mounted, which were connected to a gas bubbler. The condensate collection side of the Barrett receiver was filled with n-heptane, and the gas flow-through side was wrapped in cotton wool for the purpose of insulation. Dry air, passed over a 10 inch column filled with dry molecular sieves and Drierite, was passed through the liquid phase in the round bottom flask. The flask was heated for 4 hours at about 95° to 100° C. using a temperature controlled oil bath. Approximately 12 mL of condensate water was collected in the Barrett receiver as a result of glucose oligomerization reaction and the aldol condensation reaction to give alkylation at the C1 position. The white suspension of sugar particles disappeared as the reaction from glucose to APG proceeded until a clear solution was obtained. This demonstrated that the APG is soluble in the alcohol. The resulting APG solution was colorless, indicating that byproduct formation of colored bodies, such as furfurals, was minimized.