ChemInform Abstract: NORBORNANES. PART 10. SOLVOLYSIS OF THE STEREOISOMERIC 6‐CYANO‐2‐NORBORNYL P‐TOLUENESULFONATES. A CORRECTION

Abstract

SummaryThe solvolysis products of the stereoisomeric 6-cyano-2-norbornyl p-toluenesulfonates 1-4 (R= CN) in dioxane/water 7: 3 have been determined. In contrast to an earlier report the 6exo-cyano-2exo-norbornyl p-toluenesulfonate (1 ; R = CN) yields 30% of the 2endo-alcohol 9 (R=CN) beside the 2exo-alcohol 10 and the norbornenes 12 and 13. The results confirm that -I substituents at C(6) reduce 1,3-bridging in the intermediate norbornyl cation and hence its rate of rearrangement. The relatively high rate constants for some 6-fluoro-and 6-cyano-2exo-norbornyl p-toluenesulfonates are ascribed to C, C-hyperconjugation assisted by the conjugative effects of the 6-fluoro and cyano substituents.According to recent studies of the solvolysis rates and products of the stereoisomeric 6-substituted 2-norbornyl p-toluenesulfonates 1 [ 13, 2 [l], 3 [2] and 4 [3], electron-attracting substituents R -relative to the incipient cationic center at C (2) -lead to weakly bridged or unbridged intermediate 2-norbornyl cations 5 and 6 , whereas electron-donating substituents cause graded 1,3-bridging in the intermediate cations 7 and 82)3).