Asymmetric synthesis of 2-substituted cycloalkanecarboxaldehydes

The 1,4-addition of Grignard reagents to chiral α,β-unsaturated cyclic aldimines ($\text{3}$), prepared from the corresponding cycloalkenecarboxaldehydes ($\text{1}$) and optically active α-amino acid tert-butyl esters ($\text{2}$, was found to give, after hydrolysis, trans-2-substituted cycloalkanecarboxaldehydes ($\text{5}$) in reasonably high enantiomeric purities.