Synthesis of Taurospongin A

Two new routes to the C(1−10) carboxylic acid core of taurospongin A are presented. In the first route, overall asymmetric hydration of a C(2)−C(3) alkene is achieved by Sharpless AD and selective deoxygenation at C(2); in the second route, the C(3) stereogenic center is set by Tietze asymmetric allylation. A short synthesis of the C(1′−25′) fatty acid combines with the product from the first route to complete the total synthesis of taurospongin A.