New D-seco-taxoids were synthesized from 1-deoxybaccatinⅥand their structures were confirmed by 1H NMR,13C NMR, ESIMS and X-ray crystallography.The key step of the synthesis involved the opening of the oxetane ring u...New D-seco-taxoids were synthesized from 1-deoxybaccatinⅥand their structures were confirmed by 1H NMR,13C NMR, ESIMS and X-ray crystallography.The key step of the synthesis involved the opening of the oxetane ring under acid and basic conditions in order to obtain new multidrug resistance（MDR） reversal agents and new synthetic precursors of paclitaxel analogues.展开更多
Two novel taxoids were synthesized from 1-deoxybaccatin Ⅵ and their crystal structures were determined by X-ray crystallographic techniques. The influences of oxetane ring on molecular conformations and bioactivity w...Two novel taxoids were synthesized from 1-deoxybaccatin Ⅵ and their crystal structures were determined by X-ray crystallographic techniques. The influences of oxetane ring on molecular conformations and bioactivity were investigated. The result shows that the oxetane ring plays an important role in the conformation and bioactivity of the diterpenoid core. In the structure of compound 3, the six-membered A ring exhibits the 1,4-di-planar conformation, the eightmembered B ring adopts a boat-chair conformation, and the six-membered C ring exhibits a slightly distorted half-chair conformation. However, in D-seco-taxoid 4, the six-membered C ring exhibits a boat conformation with the release of ring strain for the D-ring opening.展开更多
基金the National Natural Science Foundation of China(No.30672506)Leading Academic Discipline Project of Shanghai Municipal Education Commission(No.J50102)
文摘New D-seco-taxoids were synthesized from 1-deoxybaccatinⅥand their structures were confirmed by 1H NMR,13C NMR, ESIMS and X-ray crystallography.The key step of the synthesis involved the opening of the oxetane ring under acid and basic conditions in order to obtain new multidrug resistance（MDR） reversal agents and new synthetic precursors of paclitaxel analogues.
基金supported by the National Natural Science Foundation of China(No.21272154 and 81202402)
文摘Two novel taxoids were synthesized from 1-deoxybaccatin Ⅵ and their crystal structures were determined by X-ray crystallographic techniques. The influences of oxetane ring on molecular conformations and bioactivity were investigated. The result shows that the oxetane ring plays an important role in the conformation and bioactivity of the diterpenoid core. In the structure of compound 3, the six-membered A ring exhibits the 1,4-di-planar conformation, the eightmembered B ring adopts a boat-chair conformation, and the six-membered C ring exhibits a slightly distorted half-chair conformation. However, in D-seco-taxoid 4, the six-membered C ring exhibits a boat conformation with the release of ring strain for the D-ring opening.
