A facile synthetic route has been developed for the preparation of pyrrolizinone derivatives employing N-allyl imides as starting materials. The nucleophilic addition of a vinyl Grignard reagent/RCM/elimination sequence afforded pyrrolizinones in good yields and has been applied for the preparation of naturally occurring quinolactacide and marinamide.

Chiral, polysubstituted proline esters, obtained via cycloaddition reactions of azomethine ylides, have been studied as organocatalysts in Michael reaction of aldehydes/ketones and vinylsulphones. Under optimised reaction conditions employing 10 mol% of the catalyst in wet CH2Cl2 yields of the products were generally good while the enantioselectivity varied reaching up to 52%.