Synthesis of Aristotelia ‐Type Alkaloids. Part VI Biomimetic Synthesis of (+)‐Aristofruticosine

( S )‐Perilla alcohol ( 5 ) was transformed into ( S )‐7‐(phenylthio)‐ p ‐menth‐1‐en‐8‐amine ( 11 ) in five steps. Condensation of this building block with 1‐(4‐methoxyphenylsulfonyl)‐1 H ‐indole‐3‐acetaldehyde ( 12 ) led to the expected imine 15 which cyclized in 54% yield to protected 20‐(phenylthio)hobartine 16 upon exposure to anh. HCOOH. Treatment of this intermediate with an alkylating reagent led to (+)‐aristofruticosine protected in the indole moiety via an intramolecular, allylic nucleophilic displacement reaction. Subsequent reductive removal of the protecting group completed the first synthesis of the Aristotelia alkaloid (+)‐aristofruticosine ((+)‐ 4 ). This straightforward synthesis confirmed the tentative structure (+)‐ 4 , proposed by Bick and Hai , and established the hitherto unknown absolute configuration of this metabolite.