反应详情

Solvents were of commercial quality and were used as received. (−)-Cinchonidine {96%; [α]23=−109.2° (c=1.5; EtOH)} was purchased from Aldrich Chemical and used as such. 5-[(1,1′-biphenyl)-4-yl]-3,4-dihydroxy-2(5H)-furanone and 5-[(4′-chloro-1,1′-biphenyl)-4-yl]-3,4-dihydroxy-2(5H)-furanone were prepared according to Dahn's method 1,2,3,4,5 starting, respectively, from biphenyl-4-carboxaldehyde and 4′-chlorobiphenyl-4-carboxaldehyde 6.