Total Syntheses Of Amaryllidaceae Alkaloids: Crinamine, Haemanthidine, Pretazettine, Tazettine, And Galanthamine

The Amaryllidaceae alkaloids possess a wide range of biological activities, such as anticancer, anticholinergic, central nervous system inhibitory, antibacterial, and analgesic activity. This thesis is aiming at the synthetic study of Amaryllidaceae alkaloids containing the quaternary carbon center, and consists of the following three parts.1. This part reviews the isolation, chemical structure identification, biological activites, and synthetic studies of the four crinine-type Amaryllidaceae alkaloids: haemanthidine, pretazettine,tazettine, and crinamine.2. The crinine-type Amaryllidaceae alkaloids including (±)-haemanthidine, (±)-pretazettine, (±)-tazettine, and (±)-crinamine were successfully synthesized using an NBS-promoted semipinacol rearrangement developed by our group and a Michael addition as the key steps, and a general strategy for synthesizing the crinine-type Amaryllidaceae alkaloids was disclosed.3. A new and short route to synthesis galanthamine has been accomplished using biomimetic phenolic oxidative coupling as key reaction over ten steps. The initial asymmetry Michael addition was tested, and the ee value of the key intermediate was up to 14%.