Dichlorocarbene adds to oxyberberine (2) to furnish the key adduct 5. Hydrolysis of 5 in dilute hydrochloric acid yields oxyberberine-13-carboxaldehyde (7). Reduction of adduct 5 with zinc in acetic acid produces 13-methyloxyberberine (1 1). Alternatively, reduction of 5 with lithium aluminum hydride in hot THF leads to enlargement of ring C with formation of the vinylic chloride 14. A complex transformation occurs when 5 is refluxed in aqueous ...
![13,13-dichloro-9,10-dimethoxy-8-(trichloromethyl)-5,6,12b,13-tetrahydro-8H-cyclopropa[3,4]isoquinolino[3,2-a][1,3]dioxolo[4,5-g]isoquinoline Structure](https://image.chemsrc.com/caspic/074/75767-38-3.png)
