Synthesis and Absolute Configuration of Strempeliopine

A rearrangement of yet another type in the vincadifformine series has been reported with 18-methylenevincadifformine (384), prepared by total 

Reagents I, NaBHaCN, AoOH, on the hydrochloride ii, CICOaCHjCCIa, CHjCIs, then NaOH, HgO ill, m-CPBA, MeOH iv, Zn, MeOH v, DDQ, dioxan vl, m-CPBA, PhH vii PhgP, AcOH. 

The indoienine 386 was neatly used in the synthesis of ( )-strempeliopine (387), the levorotatory enantiomer of which occurs in Strempeliopsis strem-pelioides K. Schum. (256). Reductive rearrangement of 3M by means of zinc and copper sulfate in acetic acid gave the indoline 388, together with 

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