all-cis-N-hydroxypyrrolidines has been developed through the formal [3+2] dipolar cycloaddition of electron-poor alkenes and nitrone ylides generatedfrom N-(methoxycarbonylmethyl)nitrones. Treatment of the nitrone with a tertiary amine in the presence of either a lithium salt or butyllithium followed by addition of the alkene at low temperature provided the product in very good chemical yield and excellent