Synthesis of phthalideisoquinolines from 3-halophthamdes and 3,4-dihydroisoquinolinium salts

Abstract

. Can. J. Chem. 59. 3055 (1981).Phthalideisoquinoline alkaloids have been synthesized by coupling appropriately substituted 3-halophthalides and 2-methyl-3,4-dihydroisoquinolinium salts in the presence of Zn(Cu) couple or metallic Zn. Both e n t i l r -o and rhr-ro isomers are formed in the reaction. The nmr spectra of the (C)-erythro-and (i)-thrro-isocordrastines have been rcinvestigated. The results, which differ from those previously reported. lead to a different conclusion regarding the conformation of the molecules. 3055 (1981) O n a synthetise des alkaloides du type phtalideisoquinoleines en faisant reagir des halo-3 phtalides convenablement substitues avec les sels de methyl-2 dihydro-3.4 isoquinolinium en presence du couple Zn(Cu) ou du Zn metallique. I1 se forme les deux isomeres ktythro et thr-60 au cours de la reaction. On a etudie de nouveau les spectres de rmn des isocordrastines ( f ) csr-ythr-o et ( f ) threo. Les resultats, qui different de ceux rapportes antlrieurement. conduisent a une conclusion differente en ce qui a trait a la conformation des molecules. CLARKE E SLEUON. LOUISE C HELLWIG JEAN-PIERRF RUDFR, ERIC W HOSKINS et DAVID B MACLEAY Can J Chem 59,[Traduit par le journal]

Diasteroselektive Hydroxyalkylierungen in 1‐Stellung von Tetrahydroisochinolinen und Synthese von Aporphin‐, Protoberberin‐ und Phthalid‐Alkaloider

“…I3C-NMR (75,47 MHz,CDCI,): 177,15 (5); 148,20 (s); 135.19 (s); 132,10 (s); 128,86 (d); 128,33 ( d ) ; 128,22 (d); 127,37 ( d ) ; 12633 ( d ) ; 125,51 ( d ) ; 125,40 ( d ) ; 79,44 (,Y); 61.00 ( d ) ; 41,24 ( I ) ; 39,27 (s); 28,73 (I); 28,47 ( 4 ) ; 27,39 ( 4 ) . MS: 319 ( I , M' ' -18), 217 (XI), 216 (98), 132 (loo), 117 (20), 105 (22), 85 (34), 77 (23), 57 (97), 43 (60), 41 (28). Anal.…”

“…H); 6,20(d,J = 4,6,4,76 (d,J = 4,6,CHN); 335 (s, CHjO); 3.77 (s, CH,O); 3,42-3,30 (m, 1 H), 3,22-3,lO (m. 1 H), 2,95 (I, J = 6,2, 2 H) (ArCH,CH,N); 1,02 (s, 1-Bu). ',C-NMR (20 MHz,CDCI,): 176,84;153,27;146,34;135,98;134,61;131,74;129,14;128,95;126,76;124,84;124,17;120.12;11 1,48;77,53;60,44;58,65;56.06;40,53;38,63;29,59;27,05. ',75,47 MHz,(D6) 128,50 (d); 128,36 ( d ) ; …”

Synthesis of phthalideisoquinolines by direct coupling of phthalide anions with 3,4-dihydroisoquinolinium salts

“…Compounds l a and 1 b have recently been described by de Silva et al (15), while the isocordrastines 2a and 2b (7,16) and the cordrastines 3a (cordrastine I) and 3b …”

“…Several reports describing new and efficient syntheses of these alkaloids based on the PerkinRobinson approach have recently appeared. In 1979 a preliminary account appeared of the reaction between 3-halophthalides and 2-methyl-3,4-dihydroisoquinolinium salts in the presence of Zn metal or Zn-Cu couple (8) and a full account of this reaction was published in 1981 (7). The validity of this approach to phthalideisoquinoline alkaloid synthesis has recently been confirmed by Shono et al (9) who carried out the same reaction in a different solvent system.…”

“…Many synthetic approaches to these alkaloids have appeared in the intervening years, which are summarized in several reviews (2)(3)(4)(5)(6) and in a recent paper (7). Several reports describing new and efficient syntheses of these alkaloids based on the PerkinRobinson approach have recently appeared.…”