Concerted and Stepwise Solvolytic Elimination and Substitution Reactions: Stereochemistry and Substituent Effects

摘要

Solvolysis of the R, R and R, S isomers 2a-X and 2b-X, respectively, (X=I, Br, OBs) in 25 vol /100 acetonitrile in water gives the elimination products 4, 5a, and 5b along with the substitution producets 2a-OH, 2b-OH, 2a- NHCOMe, and 2b-NHCOMe. The rates of elimination (K_E) increase with increasing acidity of the β-hydrogen of the substrate as expressed by a Bronsted parameter of α=0.08 and 0.07 for the iodides and the bromides, respectively.