| Abstrakt: |
The products of reaction of a series of 10 2-substituted ethanesulfonyl chlorides, X—CH2CH2SO2Cl (1), with neopentyl alcohol and pyridine-d5in nitromethane-d3showed three reaction pathways depending on the nucleofugality of the substituent, X. These routes lead, respectively, to (i) the corresponding neopentyl ester (4), via the sulfene (3) (low substituent nucleofugality); (ii) a mixture of ester 4and neopentyl ethenesulfonate (5), by the same route except for a partial loss of the 2-substituent during trapping of the sulfene (3) (intermediate nucleofugality); and (iii) a mixture of the ethenesulfonate (5) and the pyridino-betylate (4g) esters, arising from initial elimination of HX to form ethenesulfonyl chloride (2) followed by its further reaction (high substituent nucleofugality). A set of nucleofugality values closely related to, and partly complementing, those derived by Stirling and co-workers can be estimated from the product ratios in those reactions proceeding (at least in part) by route (ii) above. Old reports of anomalous products from 1,2-ethanedisulfonyl chloride (1i) and 2-chloroethanesulfonyl chloride (1j) are simply accounted for on the basis of the initial conversion to ethenesulfonyl chloride (2). |
