Chiral cycloalkylidene α,β-unsaturated iminium approach to stereoselective formal [3+3] cycloaddition reaction in spiroheterocycle synthesis
作者:Michael J McLaughlin、Hong C Shen、Richard P Hsung
DOI:10.1016/s0040-4039(00)02018-9
日期:2001.1
An approach to stereoselective formal [3+3] cycloadditionreaction using chiral cycloalkylidene α,β-unsaturated iminiums is described here leading to preparations of spiroheterocycles in modest stereoselectivity. The reversibility of 6π-electron electrocyclic ring closure did not always lead to the thermodynamically more favored product. These observations led to other useful mechanistic understanding