Reversibility cont'd HBr (g) Reaction run with BF30Et2 instead of HBr and resorcinol added to scavenge Bromine produced. Products 2 and 3 were quantitatively recovered when resubjected to the reaction conditions Used the CoCl protecting group on Nitrogen to prevent the stabilization of a benzylic carbocation This was used in reactions involving the oxirane derivative of 1 where exclusive anti addition products were formed. No ring restriction to acridine derivatives were found elimination forming H20 and Br2 have been excluded due to the reactions involving which cannot react thru a bromide assisted concerted elimination. a concerted n was also ruled out in analogous reactions of HBr and 2-bromo-1, 2-dipheny When 3 was dissolved in CH3 CN and cis-stilbene was added in the absence of acid, the products obtained were 2 and dibromostilbene PA-Bromonium 08 10/4/00 4: 10 PMReversibility cont'd 1 23 HBr (g) RT Run Solvent 12 3 1 2 3 4 * (CH2Cl)2 CHCl3 CCl4 CHCl3 25 40 44 16 24 39 36 21 15 <1 50 Products 2 and 3 were quantitatively recovered when resubjected to the reaction conditions Used the COCl protecting group on Nitrogen to prevent the stabilization of a benzylic carbocation. This was used in reactions involving the oxirane derivative of 1 where exclusive anti addition products were formed. No ring restriction to acridane derivatives were found. Concerted elimination forming H2O and Br2 have been excluded due to the reactions involving BF3OEt2 which cannot react thru a bromide assisted concerted elimination. A concerted elimination was also ruled out in analogous reactions of HBr and 2-bromo-1,2-diphenyl￾ethanol. When 3 was dissolved in CH3CN and cis-stilbene was added in the absence of acid, the products obtained were 2 and dibromostilbene. . . . . * Reaction run with BF3OEt2 instead of HBr and resorcinol added to scavenge Bromine produced. Bellucci, G.; Bianchini, R. J. Am. Chem. Soc. 1988, 110, 546 Bellucci, G.; Chiappe, C. J. Am. Chem. Soc. 1987, 109, 515 N OH Br O Cl Cl O N N Br Br O Cl 09A-Bromonium 08 10/4/00 4:10 PM