Spiro compounds have been considered key scaffolds for pharmaceutical applications. Although many synthetic methods exist for monospirocycles, fewer approaches are known for dispirocycles. Here, we report a highly cis-selective method for constructing a 5/6/5-dispirocyclic structure containing pyrrolidine and γ-lactam rings with various substit-uents from a series of N-arylpropiolamides. The high cis-selectivity would result from isomerization under thermody-namic control. Cis- and trans-diastereomers can be in equilibrium, favoring cis-adducts.
The structure of the substituent in entry 2 of Table 3 has been corrected; The substituent should be ethyl ester instead of methyl ester.