Rearrangement of O-cinnamoyltaxicin I to a novel C-13 spiro-taxane.
During the large-scale synthesis of an O-cinnamoyltaxicin I acetonide, an intermediate for the semisynthesis of 7-deoxypaclitaxel derivatives, side-product 3 was formed via a vinylogous retro-aldol reaction and a long-range hydride shift from O-cinnamoyltaxicin I (1) under alkaline reaction conditions. Compound 3 has two hemi-acetal bridges at C-1,C-9 and C-10,C-13. Compound 4 was formed from side-product 3 under acidic reaction conditions and is the first C-13 spiro-taxane described in the literature. This spiro-taxane has two acetal bridges between C-1, C-13 and C-10,C-13.
van Rozendaal
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EL
Laboratory of Organic Chemistry, Phytochemical Section, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands. Erik.vanrozendaal@BIO.OC.WAU.NL
Veldhuis
H
H
van Veldhuizen
B
B
van Beek
T A
TA
de Groot
A
A
Beusker
P H
PH
Scheeren
H W
HW
D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D000972:Antineoplastic Agents, Phytogenic / Q000138:chemical synthesis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D017239:Paclitaxel / Q000138:chemical synthesis* / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*
D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D017239:Paclitaxel