Conjugate addition of aryl nucleophiles to α,β-unsaturated cinnamic acid derivatives containing Evans type chiral auxiliaries

Cinnamides containing oxazolidin-2-one type auxiliaries have been prepared. A novel pathway to chiral 4-aryl-6-methyl-3,4-dihydrocoumrines via the asymmetric conjugate addition of arylmagnesium bromides to these cinnamides is described.

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(S)-3-[(S)-3-(2-Benzyloxy-5-methylphenyl)-3-phenylpro-pionyl]-4-phenyl-oxazolidin-2-oneC32H29NO4[α]D22 = +75 (c 1.0, CHCl3); de 100%Absolute configuration: (S)(S)