Studies toward the total synthesis of cyclodidemniserinol trisulfate. Part I: 3,5,7-Trisubstituted 6,8-dioxabicyclo [3.2.1] octane core structure construction via a convergent and a linear stereoselective synthesis

The core structure of the natural product cyclodidemniserinol trisulfate, a natural HIV-1 integrase inhibitor, was synthesized by employing intramolecular ketal formation strategy via a convergent synthesis and a linear synthesis approach, respectively. Both approaches relied on Shapless asymmetric dihydroxylation to introduce the chiral centers at 1- and 7-position, and the latter also utilized Sharpless asymmetric epoxidation to install the chiral center at 3-postion of the 3,5,7-trisubstituted-6,8-dioxabicyclo [3.2.1] octane. The established methodologies will be beneficial for further total synthesis and structural derivatization.