Asymmetric Lewis Acid-Catalyzed Diels−Alder Reactions of α,β-Unsaturated Ketones and α,β-Unsaturated Acid Chlorides
作者:Joel M. Hawkins、Mitch Nambu、Stefan Loren
DOI:10.1021/ol035524t
日期:2003.11.1
[reaction: see text] Conformational analysis, van der Waals attractions, and transition structure calculations are combined to design an asymmetric Lewis acid-catalyzed Diels-Alder reaction for simple acyclic alpha,beta-unsaturated ketones and alpha,beta-unsaturated acid chlorides, giving up to 83 and 92% ee, respectively. The two-point-binding chiral recognition mechanism, Lewis acid-Lewis base coordination
Electrochemical reduction of exo-5-acetyl-endo-6-trichloromethylbicyclo[2.2.1]hept-2-ene (2) using a mercury cathode gave chemoselectively either the corresponding monochloromethyl or dichloromethyl derivatives in high yields by selecting supporting electrolyte. The reduction of 2 using a lead cathode gave 2-acetyl-3-methylbicyclo[2.2.1]hepta-2,5-diene and cis-1-(4-vinyl-2-cyclopentenyl)-2-propanone