Malonic ester synthesis, modifie

The basic malonic ester synthesis we have outlined can be modified. Often one can advantageously use different bases as, for example, potassium tert butoxide alkyl sulfonates instead of halides polar aprotic solvents like DMSO or DMF (Sec. 1.21). 

Like the malonic ester synthesis, this synthesis, too, can be modified by changes in the base, solvent, and alkylating agent. 

Lithium N-isopropylcyclohexylamide Carboxylic acid esters from halides Synthesis with addition of 2 C-atoms Modified malonic ester synthesis... 

This is a modified malonic aster synthesis made possible by (1) the high acidity of the a-hydrogens of malonic ester (2) the extreme ease with which malonic acid and substituted malonic acids undergo decarboxylation, ... 

Recently, the Biju group demonstrated a highly enantioselective NHC-eatalyzed synthesis of functionalized cyclopentenes via o,p-unsaturated acyl azolium intermediates. This organo cascade reaetion of modified enals with malonic ester derivatives having a y-benzoyl group involves the Michael/ intramolecular aldol/p-lactonization/decarboxylation sequence to deliver functionalized cyclopentenes in good yields and excellent ee values (up to 85% yield and >99% ee) (Scheme 7.105). 

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