Abstract
Ethyl orthoformate reacts with
butane-1,2,4-triol, pentane-1,2,5-triol, and pentane-1,3,5-triol to form
2,7,8-trioxabicyclo[3,2,1]octane, 2,8,9-trioxabicyclo[4,2,1]nonane, and
2,8,9-trioxabicyclo[3,3,1]nonane respectively. Attempts to prepare the analogous
bicyclic orthoesters from glycerol and 2-hydroxymethyl-butane-1,4-diol led to
monocyclic derivatives and to polymers. The ease of formation and stability of
these bicyclic compounds are contrasted with those of
4-methyl-2,6,7-trioxabicyclo[2,2,2]octane and the results are discussed in
relation to the stereochemistry of the transition state in ester and amide
hydrolysis.