Procedure:  100 mL 2-neck flask, overhead stirrer, thermometer, adapter

                  Dissolved 4.101 g of diol I in 42 mL of CH₂Cl₂.  Stirred at rt.  Added 1.4 mL of sat. aq. NaHCO₃.  Stirred vigorously and added. 6.4 g of solid NaIO₄ portionwise over 20 min maintaining reaction temperature below 25 C.  After addition of NaIO₄ the reaction mixture was stirred for 2 h.  Added 7.0 g of MgSO₄, stirred vigorously for 15 min and filtered.  The solvent was removed by rotary evaporation.  The product was isolated by Kugelrohr distillation (aspirator) - collected only the material that distilled between 60-90 C.  The product was a clear, colorless oil. 

 

notes

 

The product is volatile and a dry ice-acetone bath was used to cool the collecting bulb of the Kugelrohr apparatus. 

 

This procedure was first reported by Schmid, et al and is an improvement on previously reported methods for the preparation of D-glyceraldehyde acetonide (see: Schmid, C.R.; Bryant, J.D.; Dowlatzedah, M.; Phillips, J.L.; Prather, D.E.; Schantz, R.D.; Sear, N.L.; Vianco, C.S.  J. Org. Chem.  1991, 56, 4056).  Saturated aqueous bicarb is employed to scavenge formic acid (produced by the cleavage of incompletely protected mannitol diacetonide) which catalyzes polymerization of the desired product. 

 

Glyceraldehyde acetonide polymerizes on standing.  However, the polymer can be stored and cracked by distillation in vacuo (60-80 C) to give back the monomer with no loss in stereochemical integrity (see: Hertel, L.W.; Grossman, C.S.; Kroin, J.S.  Syn. Comm.  1991, 21, 151).