Desaminierungsreaktionen, 51. Zerfall von Bicyclo[3.1.0]hexan‐ exo ‐6‐diazonium‐Ionen

Deamination Reactions, 51. – Decomposition of Bicyclo‐[3.1.0]hexane‐ exo ‐6‐diazonium lons The nitrous acid deamination of the amine 13 , the copper(II)‐induced cleavage of the nitrosourea 19 , and the thermolysis of the nitrosoamide 20 were used to generate the diazonium ion 7 . In contrast to previous work, performed in the presence of base, the neutral to weakly acidic conditions of the present study afforded substantial fractions (30–40%) of bicyclo[3.1.0]hex‐ exo ‐6‐yl products ( 15 ). Small quantities of bicyclo[3.1.0]hex‐ endo ‐6‐yl ( 14 ), bicyclo[3.1.0]hex‐2‐yl ( 25 , 26 ), and 3‐cyclohexen‐1‐yl ( 27 ) derivatives were also detected, the latter arising by a 1,3‐hydride shift. These results, unprecedented with higher homologs of 7 , suggest a largely „classical” bicyclo[3.1.0]hex‐6‐yl cation ( 21 ) as the initially formed intermediate. Capture of 21 is thought to compete with disrotatory transformation to the cyclohexenyl cation 12 .