名称:
Carbocationic Cyclizations: IX. Rearrangement of Long-Lived 4-(2-Biphenylyl)-1,2,3,4-tetramethylcyclobutenyl Cation into trans- and cis-4,5,6,6-Tetramethyl-4,5,6-trihydrocyclopenta[j,k]phenanthren-5-yl Cations
摘要:
According to the H-1 and C-13 NMR data, long-lived 4-(2-biphenylyl)-1,2,3,4-tetramethylcyclobutenyl cation generated by protonation of 3-(2-biphenylyl)-1,2,3-trimethyl-4-methylenecyclobutene in superacids undergoes cyclization which launches further rearrangements finally leading to formation of a mixture of trans- and cis-4,5,6,6-tetramethyl-4,5,6-trihydrocyclopenta[j,k]phenanthren-5-yl cations.