Abstract: Cephalotaxine (l), the major alkaloid produced by several species of Cephalotaxus (plum-yews), has been synthesized as its racemate in eight steps from 1-prolinol (4) and 3, 4- methylenedioxyphenylacetyl chloride (3). Cephalotaxinone (22) and demethylcephalotaxinone (19), minor alkaloids which normally occur with cephalotaxine, have been prepared as intermediates in this synthesis.
![1-(benzo[1,3]dioxol-5-yl-acetyl)-pyrrolidine-2-carbaldehyde结构式](https://image.chemsrc.com/caspic/343/38847-95-9.png)
![2-acetoxy-1-(5,8,9,10-tetrahydro-6H-[1,3]dioxolo[4',5':4,5]benzo[1,2-d]pyrrolo[1,2-a]azepin-11-yl)-propan-1-one结构式](https://image.chemsrc.com/caspic/070/38848-22-5.png)
![5,8,9,10-tetrahydro-6h-[1,3]dioxolo[4,5-h]pyrrolo[2,1-b][3]benzazepin-6-one结构式](https://image.chemsrc.com/caspic/295/38847-96-0.png)
![5,8,9,10-tetrahydro-6H-1,3-dioxolo[4,5-h]pyrrolo[2,1-b][3]benzazepine结构式](https://image.chemsrc.com/caspic/456/35667-11-9.png)
![4H-Cyclopenta[a][1,3]dioxolo[4,5-h]pyrrolo[2,1-b][3]benzazepin-1-ol,1,5,6,8,9,14b-hexahydro-2-methoxy-, (1R,3aS,14bR)-rel结构式](https://image.chemsrc.com/caspic/108/38848-21-4.png)
![2-hydroxy-1-(5,8,9,10-tetrahydro-6H-[1,3]dioxolo[4',5':4,5]benzo[1,2-d]pyrrolo[1,2-a]azepin-11-yl)-propan-1-one结构式](https://image.chemsrc.com/caspic/032/38848-23-6.png)
![1-(5,8,9,10-tetrahydro-6H-[1,3]dioxolo[4',5':4,5]benzo[1,2-d]pyrrolo[1,2-a]azepin-11-yl)-propane-1,2-dione结构式](https://image.chemsrc.com/caspic/494/38848-24-7.png)
