The asymmetric total synthesis of (+)-N-acetyl norloline

Abstract

The asymmetric total synthesis of (+)-N-acetyl norloline, the putative biogenic precursor of all known loline alkaloids, has been achieved in 12 steps from commercially available (R)-glyceraldehyde acetonide. The synthesis relies on the Rassu/Casiraghi's vinylogous aldol reaction, an intramolecular oxa-heteroconjugate addition and a reductive amination to establish the four contiguous stereogenic centers and construct the strained oxygen-bridge under mild conditions.