Simultaneous deprotection-oxidation of cyclic hemiacetals: a fine ending for a Ueno-Stork ATRC to dichloro-γ-lactones

Recently we found that a copper catalysed Ueno-Stork cyclization can be a very useful means for the expedient synthesis of dichloro-γ-lactones, but, to take advantage of this step, the method still lacks of an efficient and selective follow-up. This Letter describes our progress in that field, unveiling the use of a supported and recyclable Cr(VI) catalyst for the simultaneous deprotection and oxidation of cyclic dichloro hemiacetals.