Diastereo‐ and Enantioselective Synthesis of 2‐Substituted 3‐Trialkylstannylcyclohexanones by Michael Addition of Trialkylstannyllithium to Cyclohexenone SAMP Hydrazone

Overall yields of up to 80% are achieved in the Michael addition of trialkylstannyllithium to cyclohexenone SAMP hydrazone (S)-1 (or its R enantiomer) followed by α-alkylation. This tandem reaction provides, after oxidative cleavage of the auxiliary, 2-substituted trans-3-trialkylstannylcyclohexanones (S,S)2 (and the enantiomers (R,R)-2) in high enantiomeric purity (de ≥ 98%, ee 85 to ≥ 96%). R1, R2 are for example, nBu, Me.