146451-48-1Relevant academic research and scientific papers
Synthesis of C-Aromatic Taxinine Derivatives
Seto, Masaki,Morihira, Koichiro,Katagiri, Setsuo,Furukawa, Takashi,Horiguchi, Yashiaki,Kuwajima, Isao
, p. 133 - 136 (1993)
An oxygenated substituent at 2-position (taxane numbering) plays a critical role to determine the endo/exo cyclization into the 8-membered ring system involved in the taxane skeleton, and the aromatic taxinine derivative was prepared from the correspondin
An efficient approach toward taxane analogs: Atrop- and diastereoselective eight-membered B ring cyclizations for synthesis of aromatic C-ring taxinine derivatives
Seto,Morihira,Horiguchi,Kuwajima
, p. 3165 - 3174 (2007/10/02)
We have developed efficient methods for construction of the C-2 oxygenated aromatic C-ring taxane skeleton based on an eight-membered ring cyclization involving a Lewis acid-mediated intramolecular coupling reaction of the dienol silyl ether at C-10 and the acetal at C-9. The C-2 stereogenic center strongly influences the conformation of the forming eight-membered ring during the cyclization reaction. 1β,2α-Siloxy derivative 13b gives exo isomer 15 as the major product, and 1β,2β-siloxy derivative 13a exclusively yields endo isomer 14. Both of these cyclization products, which had undesired stereochemistry, were converted to stereochemically refined aromatic C-ring taxinine analogs by multistep transformations. The chelation-controlled, eight-membered ring cyclization of 1β,2α-hydroxy derivative 31 was found to give exclusively the desired 1β,2α,9α,10β-endo isomer 16 in good yield. This remarkably stereoselective cyclization, when combined with stereocontrolled AC ring coupling reactions, should provide an efficient, convergent route toward various taxane derivatives. The aromatic C-ring taxinine analogs could be converted to natural taxinine by further transformation of the aromatic C-ring.
