A novel C2-symmetric bis-sulfoxide 1 was synthesized as a chiral auxiliary for asymmetricdesymmetrization of meso-1,2-diols. cis-Cyclohexane-1,2-diol and cis-cyclopentane-1,2-diol were desymmetrizedvia acetalization with 1 followed by base-promoted acetal cleavage with high diastereoselectivity (>96% d.e.).
A total synthesis of (+)-aspicilin 1 was accomplished via an asymmetric desymmetrization of a meso-erythritol derivative using a C-2-symmetric bis-sulfoxide and a chelation-controlled Grignard reaction as the key steps. (C) 2000 Elsevier Science Ltd. All rights reserved.