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Carbon Participation in the Solvolysis of Tertiary Norbornyl Derivatives Norbornanes. Part 15 . 6‐substituted 2‐methylnorbornyl 2‐ exo ‐ and 2‐ endo ‐2,4‐dinitrophenyl ethers
Author(s) -
Grob Cyril A.,
Waldner Adrian
Publication year - 1983
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19830660813
Subject(s) - chemistry , 2 norbornyl cation , solvolysis , steric effects , medicinal chemistry , additive function , hydrolysis , computational chemistry , stereochemistry , inductive effect , organic chemistry , mathematical analysis , mathematics
The solvolysis rates and products of the tertiary 2‐methyl‐2‐ exo ‐ and ‐2‐ endo ‐norbornyl 2,4‐dinitrophenyl ethers 1 and 2 , (X = 2,4‐(NO 2 ) 2 2 C 6 H 3 O) have been determined. The different sensitivities of the rates of these ethers to the inductive effect of substituents at C(6) indicate that graded bridging of C(2) by C(6) occurs in the ionization of the exo ‐ethers 1 , not, however, in the ionization of the endo ‐ethers 2. In both cases hydrolysis leads to 2‐methyl‐2‐ exo ‐norbornanols only. Consequently, substitution takes place with retention at C(2) in the exo ‐series 1 and with inversion at C(2) in the endo ‐series 2. It is concluded that stereoelectronic and polar effects, rather than steric bulk effects, determine the high exo / endo rate ratios of the parent norbornyl derivatives 1a and 2a .