218932-20-8

Upstream product

• 218956-26-4 (1R,3R)-N-benzyl-6-hydroxy-8-isopropoxy-1,3-dimethyl-1,2,3,4-tetrahydroisoquinoline 

Downstream Products

• 218932-21-9 (2R,4R)-3-Benzyl-5,10-diisopropoxy-2,4-dimethyl-1,2,3,4-tetrahydro-7-oxa-3-aza-benzo[c]phenanthren-8-one 

Relevant academic research and scientific papers

First Atropo-Divergent Total Synthesis of the Antimalarial Korupensamines A and B by the "Lactone Method"

The stereoselective total synthesis of the antimalarial korupensamines A (1a) and B (1b) by application of the "lactone method" is described. Key steps of this first atropo-selective access to 5,8′-coupled naphthylisoquinoline alkaloids were the regioselective intramolecular coupling of ester 8 to give the configurationally labile lactone-bridged biaryl 9 and its atropisomer-selective cleavage with a variety of chiral and achiral H-nucleophiles, yielding the configurationally stable P-diol 10a or, optionally, the M-product 10b. From the axially chiral phenylisoquinolines thus obtained atropo-diastereodivergently, the authentic natural naphthylisoquinolines with the respective axial configurations, korupensamines A (1a) and B (1b), were obtained by completion of the second naphthalene ring, starting from the previous "bridgehead" C1 unit.

The atropo-divergent preparation of axially chiral biaryls through the 'lactone methodology': Total synthesis of korupensamine B

The regio- and stereoselective total synthesis of the antimalarial naphthylisoquinoline alkaloid and michellamine-'half', korupensamine B (1b), is described. The synthesis involves the ester-type prefixation of its protected isoquinoline moiety 3 with a monocyclic benzoic acid 2, the intramolecular coupling to give a lactone-bridged biaryl intermediate 5 with unstable axial chirality, and its atropo-divergent stereoselective cleavage optionally to the M- and P-atropisomeric alcohols 6a and 6b, respectively, followed by the construction of the second naphthalene ring from the previous C1-bridgehead. This synthesis constitutes the first atropisomer-selective access to 5,8′-coupled naphthylisoquinoline alkaloids, which only have a 'cryptic' (since endocyclic) C1-unit next to the biaryl axis.