A one-pot, three-component regiospecific synthesis of dispiropyrrolidines containing a thiophenone ring via 1,3-dipolar cycloaddition reactions of azomethine ylides

The synthesis of new dispiropyrrolidines containing a thiophenone ring has been achieved by a one-pot, three-component 1,3-dipolar cycloaddition reaction. Unsaturated thiophenone dipolarophiles were reacted with azomethine ylides, generated in situ from sarcosine and cycloketone derivatives (isatin, ninhydrin, acenaphthoquinone), to produce the corresponding cycloadducts in good yields (70–90%). The cycloaddition reaction was found to be highly regio- and diastereoselective.