Direct formylation of 9,9 '-spirobifluorene: 2-carboxaldehyde-9,9 '-spirobifluorene and 2,2 '-dicarboxaldehyde-9,9 '-spirobifluorene

The one-step formylations, using CH3OCHCl2/TiCl4 in CH2Cl2, of 9,9 ' -spirobifluorene to obtain 2-carboxaldehyde-9,9 ' -spirobifluorene and 2,2 ' -dicarboxaldehyde-9,9 ' -spirobifluorene in moderate to good yields are described. Previous works dealt with four-steps synthesis.