Ethyl‐2‐cyano‐2‐(2‐nitrophenylsulfonyloximino)acetate ( ortho ‐ NosylOXY) Mediated Acetalization and Thioacetalization of Aldehydes

We demonstrate a simple and effective methodology for acetalization and thioacetalization of aldehydes by catalytic amount of ethyl‐2‐cyano‐2‐(2‐nitrophenylsulfonyloximino)acetate (ortho‐NosylOXY), a novel peptide coupling reagent. This safe reagent successfully transforms the aldehydes into cyclic acetals, 1,3‐dithiolanes, and 1,3‐dithianes. The reaction is compatible with electron‐withdrawing and donating substituents containing aldehydes and different kinds of diols and dithiols. Also, the reaction worked well with an α,β‐unsaturated aldehyde, and an aliphatic aldehyde. Yields are impressive (71 to 95 %) at a moderate temperature and short time. Hence, broad substrate scope, high yield, easy isolation of the products, and catalytic nature of the reagent make this methodology an environment‐friendly alternative to the existing ones.