Synthesis of highly substituted oxetanesvia [2+2] cycloaddition reactions of allenoates catalyzed by a guanidine Lewis base†
Abstract
The first synthesis of highly substituted 3-alkyl-oxetan-2-ylidenes from allenoates was developed by using the bicyclic guanidine 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as an exceptionally active