Synthesis of the Tetracyclic Core (ABCE Rings) of Daphenylline

• Published in: Journal of organic chemistry Vol. 77; no. 18; pp. 8367 - 8373
• Main Authors: Fang, Bowen, Zheng, Huaiji, Zhao, Changgui, Jing, Peng, Li, Huilin, Xie, Xingang, She, Xuegong
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 21.09.2012; Amer Chemical Soc
• Subjects: Alkaloids - chemical synthesis; Alkaloids - chemistry; Bridged-Ring Compounds - chemistry; chemical reactions; chemical structure; Chemistry; Chemistry, Organic; Cyclization; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with only one n hetero atom and condensed derivatives; Lactams - chemistry; Noncondensed benzenic compounds; Organic chemistry; organic compounds; Physical Sciences; Polycyclic Compounds - chemistry; Preparations and properties; Science & Technology; Stereoisomerism; REAGENT; DAPHNILACTONE-B; BENZOMORPHANS; DAPHNIPHYLLUM ALKALOIDS; MORPHINE; CONSTRUCTION; Michael addition; Unsaturated compound; Intramolecular reaction; Brönsted acid; Friedel Crafts reaction; Benzylic compound; Nitrogen heterocycle; Lactam; Bicyclic compound; Tetracyclic compound; Chemical synthesis
• ISSN: 0022-3263; 1520-6904; 1520-6904
• DOI: 10.1021/jo301533f

A concise synthesis of the tetracyclic core (ABCE rings) of daphenylline has been accomplished involving a benzobicyclo[3.3.1] lactam as the key intermediate. This bridged bicyclic intermediate was efficiently constructed via a Brønsted acid promoted intramolecular Friedel–Crafts type Michael addition of a δ-benzyl α,β-unsaturated δ-lactam.