Benzopyrans. Part-XXVIl. Synthesis of 2-Methyl-4-oxo- 4H-1-benzopyran-3-carboxaldehyde and 3(5)-Salicyloylpyrazole from 2-Unsubstituted 4-Oxo-4H-1- benzopyran-3-carboxaldehyde - CHANDRA KANTA GHOSH (1990)