The first enantioselective synthesis of (+)-dihydrocuscohygrine 1 and cuscohygrine 2 is presented. 1 was obtained in nine steps and 30% overall yield with a ruthenium-catalyzed tandem ring rearrangement metathesis key step starting from enantiomerically pure cycloheptene-1,3,5-triol derivative 6. The unknown absolute configuration of natural dihydrocuscohygrine 1 could be determined as (S,S)-(-). Cuscohygrine 2 was obtained by Jones oxidation of 1 in quantitative yield but unfortunately with complete epimerization.

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A stereoselective synthesis of (−)-anaferine dihydrochloride has been developed. The bis(tetrahydropyridine) system 10 was formed by a tandem ring rearrangement metathesis of the chiral bis(but-3-enylamino)cycloheptene derivative 9.

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