Oxidation of Protoberberines

Protoberberinephenolbetaines are important intermediates in chemical transformations of protoberberines. In this section, their syntheses and some reactions are described. 

8-Methoxyberberinephenolbetaine (131) possesses an interesting structural feature, namely, an 8,14-dioxygenated berberine skeleton and a masked carboxylic acid at C-8. It has been converted to phthalideisoquinoline alkaloids (Section V,D,1). Treatment of 131 with methyl iodide, hydrochloric 

Conversions of 139 to phthalideisoquinoline (Section V,D,4) and isoin-dolobenzazepine alkaloids (Section V,H,2) are described later. 

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