Functionalized3-bromocoumarins 2 have been prepared by a simpleone-pot bromination/Wittig/cyclization tandem process from methyl (triphenylphosphoranylidene)acetate, N-bromosuccinimide and a series of 2-hydroxybenzaldehydes. Owing to the commercial availability of salicylaldehyde derivatives, this approach offers such a diverse range of compounds that it fulfills the recent demand for the generation
An exceptionally stereoselective and general synthesis of (Z)-α-haloacrylates, ready to undergo various synthetic transformations, has been demonstrated from α-haloacetates and aldehydes in a one-pot manner via the titanium-enolate based asymmetric aldol condensation. Besides being an expedient synthetic procedure, the ready availability of diverse α-haloacetates, exceptional stereoselectivity, and high yields make the process a versatile transformation in organic synthesis. The potential of this method in up-scaling operations has been illustrated.