75819-73-7Relevant academic research and scientific papers
Stereochemistry of acid-catalyzed cleavage of 3-chloro- and 3-bromonortricyclene in deuterated medium. Evidence for edge protonation of nortricyclenes
Werstiuk, Nick Henry,Timmins, George,Cappelli, Frank Peter
, p. 1709 - 1724 (2007/10/02)
Cleavage of 3-chloronortricyclene (4c) and 3-bromonortricyclene (4d) occurs faster than solvolysis in D2SO4-DOAc at 70-75 deg C and yields syn-7-, anti-7-, exo-5-, and endo-5-halo-exo-2-norbornyl acetates as products.That the 7-chloroacetates comprise 70percent of the reaction mixture, that 30percent of the 5-chloro-exo-2-norbornyl acetates which comprised 28percent of the reaction mixture are derived via rearrangement of the syn-7- and anti-7-chloronorbornyl cations, and that the deuterium at C-6 is at least 90percent stereochemically pure endo is evidence that cleavage of the bond farthest removed from the electron withdrawing halogen is preferred 5:1 over the other bonds of the three-membered ring.The stereochemistry of the ring-opening is rationalized on the basis of cleavage via edge-deuteronation with formation of classical halocations as intermediates.The location of deuterium in the 5-halo-exo-norbornyl acetates is used to define the pathways whereby the 5-haloacetates are formed.This study also establishes that C-6 endo deuterated 7-chloro- and 7-bromo-exo-2-norbornyl brosylates can be synthesized from the corresponding 3-halonortricyclenes.
