Palladium-catalysed spirocyclisation of 3-acetoxy-1-(4-aminoalkyl)cyclohexenes
Abstract
The 2,7-disubstituted 1-azaspiro[5.5]undecene (2; R = pentyl, R1= Bu) cannot be obtained by Pd0-catalysed cyclisation of the cyclohexenyl acetate (1; R = pentyl, R1= Bu), but the monosubstituted derivative (2; R = H, R1= CH2OCH2OCH2Ph) is readily obtained from (1; R = H, R1= CH2OCH2OCH2Ph).