Abstract
A general and effective (3 + 2) cycloaddition reaction between nitrones and allenes to synthesize fluoro‐phosphonopyrrolidin‐3‐ones, as well as spiropyrrolidin‐3‐one phosphonates is reported under microwave heating. The products have been isolated in moderate to good yields and exclusively as 4,5‐trans diastereoisomers in all transformations.