ACETOGENIC ISOQUINOLINE ALKALOIDS .50. THE SYNTHESIS OF ALL POSSIBLE ISOMERIC 6,8-DIOXYGENATED 1,3-DIMETHYL-1,2,3,4-TETRAHYDROISOQUINOLINE METHYL ETHERS - USEFUL CHIRAL BUILDING-BLOCKS FOR NAPHTHYLISOQUINOLINEALKALOIDS
G. Bringmann et al., ACETOGENIC ISOQUINOLINE ALKALOIDS .50. THE SYNTHESIS OF ALL POSSIBLE ISOMERIC 6,8-DIOXYGENATED 1,3-DIMETHYL-1,2,3,4-TETRAHYDROISOQUINOLINE METHYL ETHERS - USEFUL CHIRAL BUILDING-BLOCKS FOR NAPHTHYLISOQUINOLINEALKALOIDS, Liebigs Annalen der Chemie, (8), 1993, pp. 877-888
The practicable synthesis of all imaginable isomeric heterocyclic moie
ties 8-11 and ent-8-ent-11 of the naphthylisoquinoline alkaloids is de
scribed. The stereoinformation at C-3 is induced by asymmetric reducti
ve amination, using 1-phenylethylamines of either enantiomeric series
as chiral auxiliaries. The key step of the stereocontrolled constructi
on of the stereocenter at C-1 is the diastereoselective reduction of t
he corresponding dihydroisoquinolines, as obtained by Bischler-Napiera
lski synthesis, or the regio- and stereoselective Pictet-Spengler reac
tion of arylisopropylamines with acetaldehyde, respectively,