Short synthesis of phenylpropanoid glycosides calceolarioside-B and eutigoside-A
作者:Duc Thinh Khong、Zaher M.A. Judeh
DOI:10.1016/j.tetlet.2016.11.116
日期:2017.1
convenient 4-step synthesis of calceolarioside-B 1 and eutigoside-A 2 in high overall yield is described. The key step involved the regioselective, Me2SnCl2-catalyzed O-6 acylation of unprotected 2-phenylethyl-β-d-glucosides 5a–b with cinnamoyl chlorides 6a–b in excellent yields. Acylation at O-6 is selective with the acid chlorides used. This work serves as a model for the convenient synthesis of phenylpropanoid
Total synthesis of phenylpropanoid glycoside osmanthuside-B<sub>6</sub> facilitated by double isomerisation of glucose–rhamnose orthoesters
作者:Duc Thinh Khong、Zaher M. A. Judeh
DOI:10.1039/c7ob00198c
日期:——
A convenientsynthesis of phenylpropanoid glycoside osmanthuside-B6 is disclosed. The key steps involved regioselective coumaroylation and rhamnosylation of unprotected phenylethyl-β-D-glucopyranoside to give 2- and 3-O-rhamnosyl orthoester glucopyranosides. Rearrangement of these orthoesters followed by selective removal of their acetyl and allyl groups gave osmanthuside-B6 in 22% overall yield. The
Synthesis and Thermally Enhanced Photoinduced Orientation of Liquid Crystalline Polymer Possessing Vinyl End Group
作者:Jeong-Hwan Lee、Nobuhiro Kawatsuki
DOI:10.1080/15421400701492465
日期:2007.8.10
Methacrylate polymer liquid crystals containing p-substituted 4-cinnamoyloxybiphenyl (CB) side group were synthesized. Two vinyl end groups were introduced to investigate the influence of the end group on the photoinduced reorientation behavior. Thermally enhanced photoinduced orientation of polymer thin films was performed by irradiating with linearly polarized ultraviolet (LPUV) light and annealing. The reorientation behavior was evaluated by measuring the polarization absorption spectroscopy. When the degree of the photoreaction was around 10 mol%, the reorientation direction was parallel to the polarization of LPUV light for both polymer films. On the other hand, when the degree of the photoreaction was low, out-of-plane orientation was observed for the polymer with the longer end group.