SnCl4‑Promoted [3+2] Annulation of γ‑Butyrolactone-Fused Donor–Acceptor Cyclopropanes with Nitriles: Access to γ‑Butyrolactone-Fused 1‑Pyrrolines

The [3+2] annulation of γ-butyrolactone-fused donor–acceptor cyclopropanes with nitriles has been explored for the access of γ-butyrolactone-fused 1-pyrrolines. The annulation was promoted by tin­(IV) chloride, and the products were obtained as single diastereomers in moderate to good yields. The products were synthetically important, and a couple of them were subjected to tandem reductive ring opening/cyclization to give the respective γ-butyrolactone-fused γ-butyrolactams in good yields.