Substituted PhMgX and PhTi(OCHMe2)4MgX react with 3,5-O-isopropylidene-L-glucurono-γ-lactone 4 to give tetrads 5a-e and its stereoisomers 6a-e Tetrads 5a-e are the important intermediates in the synthesis of howiinol...Substituted PhMgX and PhTi(OCHMe2)4MgX react with 3,5-O-isopropylidene-L-glucurono-γ-lactone 4 to give tetrads 5a-e and its stereoisomers 6a-e Tetrads 5a-e are the important intermediates in the synthesis of howiinol Al and its derivatives. The stereoselectivities of substituted PhTi(OCHMe2)4Mg (5a-e:6a-e ratio, 68-72:32-28) were better than those of substituted PhMgX(33-64:67-36) in the reaction. The effects of different substitUted groups and positions (p-Me, m-Me, o-MeO, p-Cl) of the phenyl ring on their stereoselectivies were not significant.展开更多
Tris, di-( organotitanium) substituted tungstosilicates α,β - (CpTi)3(SiW9037)17– and γ-[(CpTi)2(SiW10O38)] 6– were prepared by the reaction of C2TiC12 (Cp= η-C5H5) with a,β-SiW9 O9/34(noted α,β Siv9,), γ-Si...Tris, di-( organotitanium) substituted tungstosilicates α,β - (CpTi)3(SiW9037)17– and γ-[(CpTi)2(SiW10O38)] 6– were prepared by the reaction of C2TiC12 (Cp= η-C5H5) with a,β-SiW9 O9/34(noted α,β Siv9,), γ-SiWO8/36 (noted γ-SiW10) The products were characterized by means of elemental analysis, IR, 1H NMR, 183W NMR and polarography. 183W NMR spectra of the complexes support the stoichiometry of the new heteropolyanions and the probable retention of the A-XW9 or γ-SiWlO units. And the organotitanium substituted compounds showed promising in vitro antitumor activity in two of human tumor cell lines.展开更多
文摘Substituted PhMgX and PhTi(OCHMe2)4MgX react with 3,5-O-isopropylidene-L-glucurono-γ-lactone 4 to give tetrads 5a-e and its stereoisomers 6a-e Tetrads 5a-e are the important intermediates in the synthesis of howiinol Al and its derivatives. The stereoselectivities of substituted PhTi(OCHMe2)4Mg (5a-e:6a-e ratio, 68-72:32-28) were better than those of substituted PhMgX(33-64:67-36) in the reaction. The effects of different substitUted groups and positions (p-Me, m-Me, o-MeO, p-Cl) of the phenyl ring on their stereoselectivies were not significant.
文摘Tris, di-( organotitanium) substituted tungstosilicates α,β - (CpTi)3(SiW9037)17– and γ-[(CpTi)2(SiW10O38)] 6– were prepared by the reaction of C2TiC12 (Cp= η-C5H5) with a,β-SiW9 O9/34(noted α,β Siv9,), γ-SiWO8/36 (noted γ-SiW10) The products were characterized by means of elemental analysis, IR, 1H NMR, 183W NMR and polarography. 183W NMR spectra of the complexes support the stoichiometry of the new heteropolyanions and the probable retention of the A-XW9 or γ-SiWlO units. And the organotitanium substituted compounds showed promising in vitro antitumor activity in two of human tumor cell lines.
