Trifluoroacetic acid → HCID 86736845, compound

Participants

Reaction Steps

In a process of preparing 4a-aryldecahydroisoquinolines the steps consisting essentially of the conversion of nipecotates to substituted methylenepiperidone and carboxylic ring formation according to the following reaction system: ##STR10## wherein 4-carboxymethyl-4-(3'-methoxyphenyl)-1-methyl-3-methylene-2-piperidone (29) is converted to an imidazolide (31) by the action of carbonyldiimidazole in CHCl3 /THF and subsequently with the magnesium enolate of tert-butyl hydrogen malonate to produce tert-butyl 4-[4'-[4'-(3"-methoxy-phenyl)-1'-methyl-3'-methylene-2'-oxopiperidyl]]-3-oxobutyrate (32) and this material 32 is cyclized by an alkali metal methanolate dissolved in methanol to tert-butyl 1,6-dioxo-4a-(3'-methoxyphenyl)-2-methyl-decahydroisoquinoline-7-carboxylate (33) and subsequently 33 is treated with trifluoroacetic acid in benzene and subsequent recovery by recrystallization from a benzene-hexane mixture to produce trans 1,6-dioxo-4a-(3'-methoxyphenyl)-2-methyl-decahydroisoquinoline (9).

Provenance & Evidence