First Total Synthesis of Mosin B

The first total synthesis of mosin B and a diastereomer was accomplished using asymmetric desymmetrization of the σ-symmetric diol and the Nozaki−Hiyama−Kishi reaction as the key steps. The THF core segment was stereoselectively constructed employing a stereodivergent synthesis starting from a common intermediate, 4-cyclohexene-1,2-diol, based on a desymmetrization strategy. By virtue of these synthetic results, it is suggested that the absolute configuration is 1a.