Exploring the versatility of the Johnson-Claisen rearrangement: access to functionally versatile δ-ethoxycarbonyl-α,β-unsaturated nitriles

A practical entry into δ-ethoxycarbonyl-α,β-unsaturated nitriles is described. α,β-Unsaturated aldehydes were converted to cyanohydrins, by employing either KCN in aqueous acid, or by using TMSCN with catalytic K2CO3, followed by acid hydrolysis of the TMS ether. These cyanohydrins underwent a Claisen rearrangement employing a modified Johnson-Claisen protocol to yield unsaturated nitriles in good yields and with moderate E/Z selectivity.