3-Trifluoroacetyl- and other 3-acyl-1-methyl-lactams (1-5) undergo the Robinson annelation with alpha,beta-unsaturated ketones to produce spirocyclic cyclohexenones (6), their precursors hydroxycyclohexanones (7) or 3-acyl-3-oxobutyl-lactams (8) depending on the substitution.