An asymmetric total synthesis of stereoisomers of a putative structure of 3-hydroxy-2-piperidone
alkaloid derivative is described. This route is not only concise and efficient but
also is achieved under an environmentally friendly approach. To this end, a direct
and double C–H oxidation reaction of simple benzylated piperidine and Baker’s yeast
reduction of a carbonyl group allowed the rapid access to the optically enriched (S)-1-benzyl-3-hydroxy-2-piperidone in only three steps. The NMR data agreed with those
obtained in the first total synthesis (and in discrepancy with the natural product),
however, optical rotation did not match with both neither the natural and synthetic
material.
Key words
alkaloids - 3-hydroxypiperidin-2-ones - total synthesis - environmentally friendly
- TEMPO - C–H oxidation - sodium chlorite