ALKOXYCARBONYL MOIETY AS A BLOCKING GROUP - GENERALLY USEFUL VARIATION OF THE MALONIC ESTER SYNTHESIS

A new, generally useful malonic ester synthesis has been developed on the basis of the alkoxycarbonyl moiety as a blocking group. Thus trialkyl methanetricarboxylates, symmetrical or unsymmetrical, were converted to their stable, nonhygroscopic sodio salts which were readily alkylated with multifunctional halides. Further elaboration could be carried out on the side chain, and reversion to the malonate was effected by monodecarbalkoxylation. The deblocking step occurs easily on exposure to alkoxide, diisopropylamide, or boron trichloride. When one of the esters is iert-butyl, anhydrous formic or trifluoroacetic acid also effects deblocking. © 1979, American Chemical Society. All rights reserved.