THE EFFECT OF LOCATING THE SULFONYL GROUP IN A 5-MEMBERED RING ON THEBALANCE OF ELIMINATION VS SUBSTITUTION-REACTIONS OF SULFONIC-ACID DERIVATIVES

The simplest examples of both a five-membered cyclic sulfonic anhydrid e (ethane-1,2-disulfonic anhydride, 3) and a sulfonylammonium salt (2, 2-dimethylisothiazolidinium 1,1-dioxide fluorosulfate, 13), are found to react with triethylamine and an alcohol via direct displacement at sulfur and not by way of the sulfene. When taken with previous observa tions these results lead to the conclusion that five-membered cyclic s ulfonic acid derivatives can generally be expected to react entirely b y direct displacement, even in those reactions in which the acylic or six-membered cyclic analogues react entirely via the sulfene.