Atheroline

The known alkaloids laurotetanine, V-methyllaurotetanine, noriso-corydine, atheroline, and O-methylflavinantine were isolated. A new alkaloid, nemuarine (C37H40O6N2 mp 222-223° [os] ° —42.7° 0-methyl, mp 154 -156° [a] ° —43.8°), which is the major constituent of the leaves, has structure 134 (121). 

A synthesis of homomoschatoline (1,2,3-trimethoxyoxoaporphine) via a Reissert intermediate and Pschorr cyclization has been described/ and a photolytic synthesis of atheroline (l,2,10-trimethoxy-9-hydroxyoxoaporphine) is now available/ The u.v. spectra of oxoaporphines are strongly dependent on the solvent used. ... 

The use of 2-nitrobenzyl halides in the Reissert alkylation, followed eventually by the Pschorr cyclization, has provided an attractive route to various aporphines (31). Thus this procedure had led to the synthesis of apomor-phine, ° apomorphine derivatives, atheroline, imenine, N-methyl-ovigerine, oconovine, 8-hydroxyaporphines, 10-hydroxyaporphines, ... 

Berbamine, isotetrandrine, isocorydine, atherosperminine, atherospermidine, spermatheridine, spemiatherine, atherospermoline, atheroline, moschatoline, methoxyatherosperminine... 

Nemuaron vieillardii (Monimiaceae) Laurotetanine, A-methyllaurotetanine, norisocorydine, atheroline, O-methylflavinanthine, nemuarine [368]... 

The determination of the position of the phenolic group in moschatoline is based mostly on UV data. Both moschatoline and the related alkaloid atheroline (7), obtained from the same source, show strong bathochromic shifts upon addition of base. The synthetic 1-hydroxy-... 

Mono-O-methylation of atheroline (7) using methyl iodide and methanolic sodium methoxide provided the known alkaloid 1,2,9,10-tetramethoxyoxoaporphine (6), thus confirming the skeleton of atheroline and the location of the oxygenated substituents at positions 1, 2, 9, and 10 40). 

Catalytic hydrogenation of 7a in the presence of Raney nickel followed by Pschorr cyclization, gave mainly the desired oxoaporphine 7b. Debenzylation was achieved in hydrochloric acid and tetrahydro-furan to afford atheroline in good yield. 

D ring substituents may also cleave with the aid of the C-7 keto group. The concerted loss of CH3OH (or CHgOD) from atheroline (7) is diagrammed in Scheme 8. 

Atheroline (3) H. nymphaeifolia8 H. sonora Trunk bark Root bark [4] [23]... 

A synthesis of atheroline has been achieved starting from the Bischler-Napieralski product 1 which underwent air oxidation to the imino ketone 2. In the presence of alkali and air, 2 was further oxidized to the 1-benzoyliso-quinoline 3. Debenzylation followed by photolysis in the presence of sodium hydroxide in a quartz vessel furnished atheroline (4), and its structural isomer 5 (see Scheme 14.2). ... 

---