Chiral Tert-butyl Sulfonamide-induced Taxol Side Chain And Its Analogues Synthesis Method

Paclitaxel (Taxol) is regarded as one of the clinically most effective chemotherapeutic agents. Recently, Taxol analogues have been found to exhibit greatly enhanced activities against several cancer cell lines as compared to paclitaxel. The source of Taxol is limited because of the availability of Taxus brevifolia.Semi-synthesis should be the exclusively practical way to produce taxol and it's analogues in large scale. Numerous studies have been focused on the preparation of the enantiopure taxol side chain and its analogues.In this thesis, we report a highly diastereoselective tert-butanesulfinylimine-lithium enolate addition to lead to the formation of N,O-protected-(S_R,2R,3S)-3-phenylisoserine ester 9i (yield 97%, dr>99%). After a simple modification in two steps from 9i, the β-lactam type of side chain 20 with (S_R)-tert-butanesulfinyl protecting group is readily prepared. This addition stategy is also useful for the preparation of enantiopure isoserine 9 with different substituents at position-3.