855301-80-3Relevant articles and documents
Stereoselective synthesis of 19-hydroxytaxoid by utilizing samarium(II) iodide-mediated double aldol cyclization
Ogawa, Yasuyuki,Kuroda, Kiichi,Matsuo, Jun-Ichi,Mukaiyama, Teruaki
, p. 677 - 697 (2007/10/03)
The stereoselective synthesis of new 19-hydroxytaxoid 36, possessing a double-aldol skeleton was achieved by way of B to BC to ABC ring construction. Optically active 8-membered ring 6 corresponding to the B-ring of 19-hydroxytaxol has been synthesized in high yield from epoxyketo aldehyde 8 by intramolecular samarium(II) iodide-mediated double aldol cyclization. The bicyclic compound 5 corresponding to the BC ring system was prepared from the 8-membered ring 6 by successive trimethylaluminium-assisted stereoselective conjugated addition and intramolecular samarium(II) iodide-mediated double aldol cyclization. The ABC-ring system 4 was constructed by stereoselective homoallylation and pinacol coupling cyclization with low-valent titanium. The synthesis of new 19-hydroxytaxoid 36 was accomplished from ABC ring system 4 by olefination of vicinal diol unit.