Rapid Access to trans-2,6-Disubstituted Piperidines: Expedient Total Syntheses of (-)-Solenopsin A and (+)-epi-Dihydropinidine

Abstract

Expedient syntheses of (-)-solenopsin A and (+)-epi-dihydropinidine are reported, the key step in both being the one-pot multicomponent aza-silyl-Prins condensation reaction to yield a trans dihydropyridine.

Key words

total synthesis - (-)-solenopsin A - (+)-epi-dihydropinidine - multicomponent condensation - aza-silyl-Prins reaction - trans dihydropyridine

References

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6

All compounds gave satisfactory analytical and spectroscopic data. Data for 7 and 8 in agreement with previously reported values.^2,3

7

The absence of racemisation of compounds 4-8 was judged by NMR experiments using Eu(hfc)₃ doping at each stage and comparison with the racemic series, where separation occurred.