CONVERSION OF ALDEHYDES AND KETONES INTO SELENOACETALS - USE OF TRIS-(PHENYLSELENO)BORANE AND TRIS-(METHYLSELENO)BORANE

In the presence of trifluoroacetic acid, aldehydes and ketones react with tris(phenylseleno)borane and with tris(methylseleno)borane to give the corresponding bis(phenylseleno)- and bis(methylseleno)acetals, respectively. Suitable reaction periods lie in the approximate range 20 min-24 h and generally about 12 mol % (based on the carbonyl compound) of TFA is required. The borane reagents are not suitable for α,β-unsaturated carbonyl compounds, but, where the reagents are applicable, yields averaged 78%. © 1979, American Chemical Society. All rights reserved.