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(iPrO)3TiCl-induced reactions of α- and β-4(20)-epoxy-5-hydroxytriacetyltaxicin I

✍ Scribed by Qian Cheng; Takayuki Oritani; Tohru Horiguchi

Publisher: Elsevier Science
Year: 1999
Tongue: French
Weight: 592 KB
Volume: 55
Category: Article
ISSN: 0040-4020
DOI: 10.1016/s0040-4020(99)00707-3

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✦ Synopsis

Chlorotitanium triisopropoxide-induced reaction of (x-4(20)-epoxy-5-hydroxytriacetyltsxicin 12 gave a 4-hydn)xymethylene-5-one'4 and a 4-hydroxy-4-chloromethylene $, while the corresponding 1~-4(20)-epoxide 3 gave a 3,8-cyclopropane 6 and a 6•8•5 ring system 7. Moreover, boron Irifluoride-induced reaction of the (x-.4(20)-epoxide 2 yielded a 6/8/6/7 ring system g and an A-ring contracted alcohol derivative 9. Plausible mechanisms of these reaclions are proposed.

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