1‐Formyl‐ and 1‐Diazoalkanesulfonates

The deprotonation of the neopentyl, isobutyl and isopropyl esters of methane‐ and ethanesulfonic acid with n ‐butyllithium and subsequent reaction with ethyl formate afforded the corresponding 1‐formylalkanesulfonates in 77–90% yield. 1‐(Methoxymethylene)alkanesulfonates could be obtained by additional treatment with dimethyl sulfate and base, as examplified in the case of neopentyl 1‐formylethanesulfonate. Furthermore, the formylated sulfonates were converted into the stable 1‐diazoalkanesulfonates in 28–65% yield employing arylsulfonyl azides as diazo group transfer reagents. The chemical behaviour of the novel 1‐diazoalkanesulfonates resembles that of 1‐diazoalkanephosphonates, e.g., deprotection to the 1‐diazoalkanesulfonate anion resulted in rapid denitrogenation. The thermolysis of isobutyl 1‐diazoethanesulfonate in an inert solvent afforded isobutyl vinylsulfonate as the major product.