Jean-Christophe Vanherck

Cerium(IV)-Catalyzed Deprotection of Acetals and Ketals under Mildly Basic Conditions.

Smooth and quantitative deprotection of a wide range of acetals and ketals [Eq. (a); R, R(1)=alkyl, aryl, H] under neutral to mildly basic conditions was achieved with catalytic quantities of cerium ammonium nitrate (CAN). The reaction conditions are compatible with a variety of sensitive functional groups, and aldehydes can be liberated from acetals without being oxidized to the corresponding carboxylic acids.

Efficient and convergent stereocontrolled spiroannulation of ketones

Upon treatment with t BuOK/H2O, a variety of omega-halo-beta-keto-ketals undergo smooth cyclisation, affording in excellent yields mono-protected [n,m] spiro bicyclic diketones. This transformation is highly stereoselective producing, in all cases, the diastereoisomerically pure spiro derivatives