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OXIRANES. PART I: ACID CATALYZED RING OPENINGS OF CHALCONE OXIDES. PART II: SURVEY OF COUPLING CONSTANTS
Abstract
Part I. Product and kinetic studies were carried out on a series of chalcone oxides using several acids as catalyst. Most reactions demonstrated a preference for erythro products, less nucleophilic solvents however tend to favor threo products. Hammett treatment of kinetic data showed a large amount of charge development in the transition state--(rho) = -4.9. Calculation of activation parameters indicated the ring opening process was entropy dominated. Part II. ('3)J(,CH) was studied for a number of oxiranes. This coupling constant was found to be small but regular in variance. The coupling constant is between 0-2 Hz for trans nuclei and 2-4 Hz for cis nuclei. Changing hybridization of the carbon had little effect upon the magnitude of the coupling constants. Oxiranes were compared to thiiranes, cyclopropanes and aziridines. The magnitude of the coupling was seen to vary according to the heteroatom present in the following manner X = O < N < S < CR(,2).
Subject Area
Organic chemistry
Recommended Citation
DURHAM, DANA LYNN, "OXIRANES. PART I: ACID CATALYZED RING OPENINGS OF CHALCONE OXIDES. PART II: SURVEY OF COUPLING CONSTANTS" (1981). ETD collection for University of Nebraska-Lincoln. AAI8113281.
https://digitalcommons.unl.edu/dissertations/AAI8113281