Novel methods for synthesizing 2-chloroaldehyde from carbonyl compounds and converting it into 2-hydroxyaldehyde derivatives

2-Chloroaldehyde derivatives were synthesized from carbonyl compounds with [chloromethyl (dimethyl)sulfonium trifluoromethanesulfonate, (1)] and DBU in THF in good yields. Further, 2-chloroaldehyde derivatives were converted into the corresponding 2-hydroxyaldehydes by treating the derivatives with n-Bu4NOH in good yields with the inverted configuration. The stereochemistry of all the products were determined by NMR (NOE).