Lycorine-type alkaloids are privileged structures in drug development due to their attractive biological activities. In this paper, the carbonyl on the C ring was proved to have played a critical role in stereoselectivity during the synthesis process, and the galanthan skeleton with acis-B/C ring is more thermodynamically stable in its presence. Furthermore, the total synthesis of (±)-β-lycorane was successfully completed by employing the Michael addition reaction to construct the galanthan skeleton with atrans-B/C ring. This system might be applied to other structural types with similar stereochemistry setting. © The Royal Society of Chemistry 2021.