STEREOSELECTIVE ALKYLATION OF CYCLIC AND ACYCLIC CHIRAL BETA-ENAMINO KETONES LITHIUM DIANIONS - SYNTHESIS OF EITHER (R)-CHIRAL OR (S)-CHIRAL 1,3-DIKETONES

The synthesis of either (R)- or (S)-chiral 1,3-diketones through asymmetric gamma alkylation reaction of cyclic and acyclic chiral beta-enamino ketones was here performed. The alkylation takes place with good yields and high d.e. in HMPA/THF. Both the pure enantiomers of 1,3-diketones can be formed by simple hydrolysis of the epimeric beta-enamino ketones obtained with this method, choosing the suitable synthetic strategies. An explanation of the asymmetric induction was proposed.