190122-97-5Relevant academic research and scientific papers
Short Synthesis of Phenylpropanoid Glycosides Calceolarioside A and Syringalide B
Khong, Duc Thinh,Judeh, Zaher M. A.
, p. 1079 - 1083 (2018/05/01)
An efficient and practical three-step synthesis of phenylpropanoid glycosides calceolarioside A and syringalide B in >62% overall yield is disclosed. The key step involves the chemoselective and regio selective direct O -4 cinnamoylation of unprotected 2-phenylethyl-β- d -glucosides with cinnamic anhydrides using a chiral 4-pyrrolidinopyridine organocatalyst. This approach serves as a model for the short synthesis of phenylpropanoid glycosides acylated at O -4 without protection/deprotection steps.
Short synthesis of phenylpropanoid glycosides calceolarioside-B and eutigoside-A
Khong, Duc Thinh,Judeh, Zaher M.A.
, p. 109 - 111 (2016/12/23)
A 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 glycosides acylated at O-6.
Total synthesis of phenylpropanoid glycoside osmanthuside-B6 facilitated by double isomerisation of glucose-rhamnose orthoesters
Khong, Duc Thinh,Judeh, Zaher M. A.
, p. 2638 - 2646 (2017/04/03)
A convenient synthesis 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 rearrangement involved a newly discovered glucose-rhamnose orthoester double isomerization process that has the potential to provide a convenient access to many complex phenylpropanoid glycosides. The synthetic route developed is envisioned to serve as a model for the preparation of phenylpropanoid glucosides having a (substituted) cinnamoyl moiety at O-6 and a saccharide moiety at O-3.
Short synthesis of phenylpropanoid glycoside grayanoside-A and analogues
Khong, Duc Thinh,Judeh, Zaher M.A.
supporting information, p. 50 - 53 (2016/11/30)
A short synthesis of phenylethyl glycosides grayanoside-A 1, 2 and analogues 3–4 in high 43–65% overall yields is described. The main synthetic step involved regioselective O-6 acylation of unprotected 2-phenylethyl-β-D-glucoside 7 with cinnamoyl chlorides 8a-d using Me2SnCl2as catalyst. The acylation at O-6 is regioselective regardless of the type of cinnamoyl chloride used. Protection/deprotection steps of the glucoside core were not necessary. The synthetic route is generally applicable for the synthesis of phenylpropanoid glycoside class of compounds acylated at O-6.
Total synthesis of the phenylpropanoid glycoside, grayanoside A
Zhang, San-Qi,Li, Zhong-Jun,Wang, An-Bang,Meng-Shen, Cai,Feng, Rui
, p. 281 - 285 (2007/10/03)
Grayanoside A, 2-(4-hydroxyphenyl)ethyl 6-O-feruloyl-β-D-glucopyranoside, was synthesized for the first time by using chloroacetyl groups for the protection of hydroxy functions. 2-(4-Allyloxyphenyl)ethyl 4-O-[(4-O-allyl)feruloyl]-2,3,6-tri-O-chloroacetyl-β-D-glucopyranoside (12) was synthesized from 2-(4-allyloxyphenyl)ethyl 4,6-O-benzylidene-β-D-glucopyranoside (8) in four steps with the goal of preparing syringalide B. It was found, however, that the feruloyl group migrated from the 4- to the 6-position of the glycopyranoside during the deprotection of 12.
