184868-99-3Relevant academic research and scientific papers
Taxane diterpenes 3: Formation of the eight-membered B-ring by semi-pinacol rearrangement
Magnus, Philip,Diorazio, Louis,Donohoe, Timothy J.,Giles, Melvyn,Pye, Philip,Tarrant, James,Thom, Stephen
, p. 14147 - 14176 (2007/10/03)
The substituted furan carboxaldehyde 15 was converted into enone 20 via a stereoselective intramolecular pyrylium ylide-alkene cyclization. Subsequent elaboration of 20 into the triflate 23, followed by solvolysis in acidic trifluoroethanol resulted in quantitative rearrangement to the taxane B/C core 24. At a higher oxidation level 27 was ring expanded to give 28. The ring expanson strategy could also be initiated by β-elimination of the 3α,10α-oxido bridge. Treatment of 50 with MeOH at reflux gave 52. Similar transformations in the 7-oxy series resulted in ring B expansion of 67 to give 68, and 75 to give 76.
