Bicyclo[3.3.1]nonanes as synthetic intermediates. Part 21.1 Enantiodivergent synthesis of the cis,cis 2,6-disubstituted piperidin-3-ol chiral building block for alkaloid synthesis

Enantiodivergent synthesis of the enantio-pure cis,cis 3-protected 2,6-disubstituted piperidin-3-ol 1 has been achieved via a biochemical method, and the absolute stereochemistry of (+)-1 has been established by its conversion into the known piperidine (-)-17. The utility of 1 as a chiral building block for alkaloid synthesis is demonstrated by the total synthesis of (-)-cassine and (+)-spectaline.