title: Benzolactams. 4. Reaction of 3',4'- or 4',5'-dialkoxy-substituted 1-(2'-Bromobenzyl)-2-ethoxycarbonyl-1,2,3,4-tetrahydroisoquinolines with alkyllithium. 1,2 and 1,4 additions of alkyllithium to benzolactams.
abstract: Treatment of 1-(2'-bromo-3',4'-dialkoxybenzyl)-1,2,3, 4-tetrahydroisoquinoline carbamates, 1a,c, with excess alkyllithium gave 8-oxoberbines, 2a,c, which were successively attacked in situ with another molecule of alkyllithium to give 1,2 and/or 1,4 addition products. A primary alkyllithium, such as MeLi or BuLi, gave a 1,2 addition product, 8-methyleneberbine 9a or 8-butylideneberbine 3a. t-BuLi preferred 1,4 addition, followed by elimination of the alkoxy group, to give 9-tert-butyl-8-oxoberbine 6a or 7c. s-BuLi gave a mixture of 1,2 and 1,4 addition products, 1-[2'-(2' '-methylbutyryl)benzyl]-1,2,3,4-tetrahydroisoquinoline 4a and 9-s-butyl-8-oxoberbine 5a. Similar treatments of carbamate 1b having no alkoxy group at its 3' position gave 1,2 addition products, 8-butylideneberbine 3b, 1-[2'-(2' '-methylbutyryl)benzyl]-1,2,3, 4-tetrahydroisoquinoline 4b, and 1-(2'-pivaloylbenzyl)-1,2,3, 4-tetrahydroisoquinoline 6b, in all cases. Reactions of 1a with s-BuMgCl and isoPrMgCl also gave the 1,4 adduct, 5a, and its 9-isoPr analogue, 12a. Treatment of 9a with excess NaBH(4) in AcOH gave (+/-)-coralydine (10b).
authors.affiliation: Laboratory of Organic Synthesis, Division of Molecular Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan. orito@org-mc.eng.hokudia.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Orito
authors.forename: M
authors.initials: M
authors.lastname: Miyazawa
authors.forename: R
authors.initials: R
authors.lastname: Kanbayashi
authors.forename: T
authors.initials: T
authors.lastname: Tatsuzawa
authors.forename: M
authors.initials: M
authors.lastname: Tokuda
authors.forename: H
authors.initials: H
authors.lastname: Suginome
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D007202:Indicators and Reagents; D007546:Isoquinolines / Q000138:chemical synthesis*; D007769:Lactams / Q000138:chemical synthesis*; D018020:Lithium Compounds
chemical_list: D000970:Antineoplastic Agents; D007202:Indicators and Reagents; D007546:Isoquinolines; D007769:Lactams; D018020:Lithium Compounds