An Approach to Total Synthesis of (+)-Lycoricidine
A convergent synthesis of a protected version of (+)-lycoricidine has been accomplished in 13 steps from L-arabinose.Preparation of the aminocyclitol moiety 50 employed a novel vinylsilane-terminated N-sulfonyliminium ion cyclization of vinylsilane aldehyde 42.Closure of the B-ring using an intramolecular Heck reaction afforded lycoricidine derivative 58.An unexpected cyclization of vinylsilane aldehyde 42 allowed for the stereodivergent preparation of semiprotected conduritols 43 and 45.