Synthesis of novel 4'-carbon-substituted BCA derivatives based on radical cyclization.
Synthesis of (+/-)-4'-carbon-substituted BCA analogues (3) was carried out. Stereospecific construction of the cis-disposed 4'-carbon-substituent and 5'-hydroxy-methyl group was secured by employing the bicyclo-[3.3.0]lactone 11 as a key intermediate, which was prepared by radical-mediated 5-exo-trig cyclization of the phenylselenomethyl ester 10. After manipulation of the double bond of 11, 6-chloropurine was introduced based on the Mitsunobu reaction of the allyl alcohol 15. Ammonolysis of the resulting carbocyclic nucleoside led to the adenine derivative 16. Saponification of the bicylic lactone furnished the 4'-carboxylic acid 17 which serves as a precursor for other 4'-carbon-substituted analogues.
Kumamoto
Hiroki
H
School of Pharmaceutical Sciences, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
Takahashi
Nonoko
N
Shimamura
Tomomi
T
Tanaka
Hiromichi
H
D000225:Adenine / Q000031:analogs & derivatives*; D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000737:chemistry; D003517:Cyclopentanes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D000998:Antiviral Agents; D003517:Cyclopentanes; D000225:Adenine