• Journal of the Korean Chemical Society
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• v.53 no.3
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• pp.340-344
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• 2009

HEMA/vinyl-substituted polyphosphazene was prepared by the ring-opening polymerization of phosphonitrillic chroride trimer at $200{\sim}300\;{^{\circ}C}$, followed by Grignard reaction with vinyl magnesium bromide and then by the reaction with HEMA(2-hydroxyethyl methacrylate). HEMA/vinyl-substituted polyphosphazene was copolymerized with EGDMA(ethylene glycol dimethacrylate; used as a cross-linker for the free-radical copolymerization), NVP (N-vinyl-pyrrolidone) in the presence of AIBN (azobisisobutyronitrile) as a radical initiator. The oxygen transmissibility, water content and visible-ray transmissibility of the resulting copolymer were measured to be Dk/t 88, 30.89% and 87%, respectively, indicating that the copolymer can be used as a good contact lens material.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1531-1534
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• 2009

(2S,3R)-3-Hydroxy-2-(hydroxymethyl)-3,6-dihydro-2H-pyridine 8, an important precursor for the synthesis of polyhydroxylated piperidine azasugars, has been prepared from L-serine. Highly stereoselective nucleophilic addition to amino aldehyde 5 gave the corresponding allylic alcohol 6 which proceeded to give dihydro-2H-piridine 7a via a Grubbs II catalyzed RCM. Stereoselective H-bond directed epoxidation of allylic alcohol led to the oxiranyl alcohol 9 which was easily converted to L-deoxyaltronojirimycin by regioselective ring opening.

• KSBB Journal
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• v.11 no.3
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• pp.263-269
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• 1996

Anticancer agent taxol was synthesized from baccatin III which was extracted from cell cultures of European yew, Taxus baccata Pendula. Callus and suspension cultures of T. baccata Pendula showed the formation baccatin III. The content of baccatin III in cell cultures reached 0.015% (w/w) on dry weight basis. The semisynthetic approaches were made with baccatin III and taxol side chain. To prepare taxol side chain, (-)-N-((S)-2-hydroxy-1-phenylethyl) benzamide was synthesized first from (S)-(+)-phenylglycine. Then (-)-N-((IS,2S)-2-hydroxy-1-phenyl-3-butenyl) benzamide was synthesized with vinyl magnesium bromide. The synthesis of (2R, 3S)-(-)-2-(1-ethoxyethoxy)-3-phenyl-3-(phenylmethanamido) propanoic acid with RuCl3, catalyst was the final step to prepare taxol side chain. The semisynthetic reactions yielded 0.0002% taxol, 0.0005% 7-epi-10-deacetyltaxol, and unidentified taxanes on dry weight basis. It is suggested that the semisynthesis of taxol from baccatin III could be an alternative source of taxol and related taxanes.