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Updated: Jul 14, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Stereoselective iodocyclization of (S)-allylalanine derivatives: gamma-lactone vs cyclic carbamate formation
Mariella Pattarozzi1, Cristiano Zonta, Quirinus B Broxterman
1Dipartimento di Scienze Chimiche and ITM-CNR, Università di Padova, via Marzolo 1, I-35131 Padova, Italy.
Abstract:
An efficient procedure for highly chemo- and stereoselective cyclization of (S)-allylalanine derivatives is reported (diastereomeric ratios up to 96:4) where the reaction course can be completely controlled by switching from gamma-lactones to cyclic carbamates simply with the proper choice of the amino acid protecting groups. Both processes are stereoconvergent and afford the (S,S)-products in high yields, short reaction times, and mild reaction conditions.
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