Oxidation of Monotetrahydropyranylated Short-Chain Symmetrical Diols

Abstract

The free hydroxyl functions of monotetrahydropyranylated three- to five-carbon symmetrical primary diols are oxidized to aldehydes, without cleavage of the protective group, by using pyridinium dichromate in CH₂Cl₂ and anhydrous MgSO₄ as a water scavenger. The oxidation procedure is improved for these specific compounds since over oxidation to carboxylic acids and formation of dimeric esters are suppressed.

Keywords:

• 3-(Tetrahydro-pyran-2-yloxy)-propionaldehyde
• 4-(Tetra- hydro-pyran-2-yloxy)-butyraldehyde
• 5-(Tetrahydro-pyran-2-yloxy)-pentanal
• Pyridinium dichromate

Acknowledgments

I thank Bruce W. Zilkowski and Robert J. Bartelt for acquiring mass spectral data, David Weisleder for acquiring NMR spectra, and Robert J. Bartelt for helpful discussions.