A large, magneticstir bar isadded to the flask that contains the crude solid diacetonide from procedure Aabove and 700–800 mL of dichloromethane (10 mL/g of diacetonide) is added. The flask is equipped with a condenser and heatingmantle, and the slurry is stirred vigorously and heated to reflux until thesolids are digested to an even consistency. The mantle is removed, the slurryis allowed to cool below reflux, and Celite (10 g) is added with stirring. The contents are furthercooled to room temperature and vacuum-filtered through a pad of Celite on a glass frit filter into a three-necked,2-L vessel. The flask is rinsed with 50 mL of dichloromethane and the rinse is filtered through thefunnel. The 2-L vessel is then equipped with an overhead stirrer, thermometer, and water bath,and stirring is begun at 300–350 rpm. A solution of 30–40mL of saturated aqueous sodium bicarbonate (0.4 mL/g of diacetonide) is added with stirring,followed by 130–140 g of sodiummetaperiodate (2.0 mol equiv), addedportionwise over 2–3 min. The resulting mixture is stirred while the internaltemperature is maintained below 35°Cwith water bath cooling. After the solution is stirred for 2 hr, 35–50 g of magnesium sulfate (0.5 g/g of diacetonide) is added andstirring is continued for 20 min. The slurry is vacuum-filtered through a glassfrit filter into a 2-L, one-necked, round-bottomed flask.The filter cake is removed, transferred back into the three-necked vessel, 200 mL of dichloromethane isadded, and the resulting slurry is stirred for 10 min. The slurry isvacuum-filtered and the filtrate is added to the one-necked flask.
The filtrate-containing flask is equipped with a 12″-Vigreux column, distillationhead, receiver, and heating mantle, and dichloromethane is removed by distillation (headtemperature to 40°C). Theresidual oil is cooled and transferred to a 250-mL,round-bottomed flask and the flask is equipped with a simpledistillation head, cow receiver, and heating mantle. After a brief forerun (2–3 g),product is collected by distillation at 30 mm(65–120°C)into a chilled receiver (5°C)to afford 54–68 g(75–85%) of crude 2,3-O-isopropylidene-D-glyceraldehyde. The crudeproduct is transferred to a 100-mL, round-bottomed flaskequipped with a 6″-Vigreux column, cowreceiver, and heating mantle, and redistilled at 30 mm, collecting the fraction distilling at 67–73°Cinto a chilled receiver to afford 50–64 g of product (70–80%,34–45% overall).
【Organic Syntheses, Coll. Vol. 9, p.450; Vol. 72, p.6】
【 J. Org. Chem. 2007, 72, 3155–3157】
【TetrahedronLetters，1990, Pages 463-464】