The molecular structure of 6‐(bromomethyl)‐1,2,4‐trichloro‐3‐ethoxy‐3,7,7‐trimethoxybicyclo[2.2.1] heptane; an X‐ray study

Abstract

AbstractHydrolysis of 6‐(bromomethyl)‐ 1,2,4‐trichloro‐3,7,7‐trimethoxybicyclo[2.2.1] hept‐2‐ene with perchloric acid in aqueous ethanol yields inter alia the title compound. X‐ray analysis proved the positioning of the substituents to be 6‐endo‐(bromomethyl)‐2‐endo‐chloro,3‐endo‐ethoxy, which is evidence that the addition in this case follows an endo‐tram mechanism.The title compound crystallizes in the monoclinic space group P21/n with a = 10.504 Å, b = 10.507 Å, c = 15.783 Å, γ = 92.20° and Z = 4. The structure was solved by conventional techniques to an R = 0.063 using Mo(Zr) diffractometer data. The effect of the substitution on the conformation of the norbornane skeleton is discussed, as well as the geometry of the acetal groups in terms of the anomeric effect.