Unusual boron trifluoride-catalyzed reactions of taxinine derivatives with α- and β-4(20)-epoxides

✍ Scribed by Hirokazu Hosoyama; Hideyuki Shigemori; Jun'ichi Kobayashi

• Publisher: Elsevier Science
• Year: 1999
• Tongue: French
• Weight: 248 KB
• Volume: 40
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(99)00135-5

✦ Synopsis

Boron trifluoride-catalyzed reaction of 13-4(20)-epoxy-5-O-triethylsilyltaxinine A (1) gave the 3,5-diene (3) and the 3,8-cyclopropane (4) derivatives, while the similar reaction of the corresponding {x-4(20)-epoxide (2) afforded the ring contracted derivative (5) and its hemiacetal dimer (6). Plausible mechanisms of these reactions containing 1,2-hydride shift (3 and 4 from 1) or pinacol-type rearrangement (5 and 6 from 2) are proposed.