Stereoselective Approach towards the Synthesis of 3R, 5 S Gingerdiol and 3 S, 5 S Gingerdiol

An operationally simple and concise stereoselective synthesis of both natural 3R, 5 S gingerdiol and 3 S, 5 S gingerdiol has been achieved from achiral n-heptanal by employing iterative proline catalysed alpha-aminoxylation, followed by Horner-Wadsworth-Emmons or Wittig olefination reactions as key steps. The adducts formed in high enantiopurity as well as syn or anti-1,3-diols units were synthesized with excellent diastereoselectivity from gamma-hydroxy aldehyde by using D or L- proline.