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Dehydronorhydrastine methyl ester

The first conversion of protoberberines to phthalideisoquinoline alkaloids was achieved by Moniot and Shamma (88,89). 8-Methoxyberberinephenol-betaine (131), derived from berberine (15) (Section III,B,2), is an attractive compound having a carboxyl group masked as an imino ether in ring B. The masking was uncovered by hydration with water-saturated ether to furnish dehydronorhydrastine methyl ester (367) (Scheme 65). On N-methylation (68%) and subsequent sodium borohydride reduction (90%), 367 provided (+ )-/ -hydrastine (368) and ( )-a-hydrastine (369) in a 2 1 ratio. Compound 367 was converted to dehydrohydrastine (370), which also afforded 368 and 369 by catalytic hydrogenation. [Pg.195]

Solutions of the betaine 363 in wet ether are slowly hydrolyzed to the methyl ester of dehydronorhydrastine (377). ° In contrast, when hydrolysis... [Pg.68]

See other pages where Dehydronorhydrastine methyl ester is mentioned: [Pg.91]    [Pg.91]    [Pg.91]    [Pg.91]    [Pg.91]    [Pg.91]    [Pg.91]    [Pg.91]   
See also in sourсe #XX -- [ Pg.85 , Pg.91 ]

See also in sourсe #XX -- [ Pg.85 , Pg.91 ]

See also in sourсe #XX -- [ Pg.85 , Pg.91 ]

See also in sourсe #XX -- [ Pg.236 ]

See also in sourсe #XX -- [ Pg.85 , Pg.91 ]



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