Quinolizidines. XXI. Syntheses of (±) - and (-) -Alancines

• Published in: Chemical & pharmaceutical bulletin Vol. 35; no. 8; pp. 3470 - 3474
• Main Authors: FUJII, TOZO, OHBA, MASASHI, YONEZAWA, ASAKO, SAKAGUCHI, JUN
• Format: Journal Article
• Language: English
• Published: Tokyo The Pharmaceutical Society of Japan 1987; Maruzen
• Subjects: alancine 13C-NMR; alancine hydrochloride; alancine IR; Alangium alkaloid; ankorine 13C-NMR; benzyl ether hydrogenolysis; Chemistry; chiral synthesis; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with only one n hetero atom and condensed derivatives; Organic chemistry; Preparations and properties; racemic synthesis; Alkaloid; Hydrochlorides; Angular nitrogen heterocycle; Enantiomer; Bicyclic compound; Racemate; Debenzylation; Aromatic compound; Infrared spectrum; NMR spectrum; Circular dichroism
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.35.3470

The first total synthesis of the Alangium alkaloid alancine (10) has been achieved in the form of a racemic modification by means of catalytic hydrogenolysis of the tricyclic amino acid (±) -9. Treatment of (±) -10 with aqueous HCl afforded the hydrochloride salt (±) -11. A parallel synthesis starting with (-) -9 gave (-) -alancine [(-) -10] as well as its hydrochloride [(-) -11] in good yields. The synthetic hydrochloride (-) -11 was found to be identical with a sample isolated from Alangium lamarckii THW., indicating that the natural sample, previously considered to be in the free base form [(-) -10], was actually in the hydrochloride form [(-) -11].