- Total Synthesis of the Natural Products Ulmoside A and (2 R,3 R)-Taxifolin-6- C -β- d -glucopyranoside
-
An efficient first total synthesis of highly polar ulmoside A and (2 R,3 R)-taxifolin-6- C -β- d -glucopyranoside, useful for the prevention of metabolic disorders, has been described. Key elements of the synthesis include a Sc(OTf) 3-catalyzed regio- and stereoselective C -glycosidation on taxifolin in 35percent yield with d -glucose and chiral semipreparative reverse-phase high-performance liquid chromatography (HPLC) for the separation of both taxifolins and the diastereomeric mixture of taxifolin-6- C -β- d -glucopyranosides. Correlation of the analytical data of synthetic ulmoside A and its diastereomer with a natural ulmoside A sample confirmed the assigned absolute stereochemistry of the natural products.
- Batchu, Venkateswara Rao,Dorigundla, Aravind Reddy,Gurrapu, Raju,Macha, Lingamurthy,Vanka, Umamaheswara Sarma
-
supporting information
p. 1097 - 1101
(2020/07/03)
-
- Efficient and versatile synthesis of 5-O-acylquinic acids with a direct esterification using a p-methoxybenzyl quinate as a key intermediate
-
An efficient and versatile synthesis of 5-O-acylquinic acids from commercially available (-)-quinic acid was accomplished. We designed p-methoxybenzyl quinate as a key intermediate, and two problems, the esterification of the sterically hindered 5-OH group for the concise divergent synthesis and the low yield of the final deprotection step, were solved. For the first problem, we improved Tanabe's method, TsCl/NMI-mediated esterification using free carboxylic acids, by the addition of i-Pr2NEt. For the second problem, we established a TFA- or BCl3/C6HMe5-catalyzed deprotection reaction for the final deprotection step. 5-O-Acylquinic acids were synthesized in seven steps with 45-60% overall yield.
- Oyama, Kin-Ichi,Watanabe, Noriyuki,Yamada, Tomomi,Suzuki, Masako,Sekiguchi, Yukiko,Kondo, Tadao,Yoshida, Kumi
-
p. 3120 - 3130
(2015/05/04)
-
- Synthesis and biological evaluation of a natural ester sintenin and its synthetic analogues
-
Synthesis of 3-(3,4-dimethoxyphenyl)propyl-3-(3,4-dimethoxyphenyl) propanoate (18), a cytotoxic natural ester, was carried out by a convenient synthetic path with a total yield of 49%. Sixteen of its analogues (19-34) were also prepared. Seventeen unsaturated derivatives of 18, compounds 1-17, were also synthesized to examine the structure-activity relationship of this type of ester. All of the synthetic compounds were passed through the cytotoxicity screenings on human tumor cell lines, such as PC-3, Hela, A549, BEL7404, CNE, and KB. Some of the esters exhibited moderate inhibitory effects on these tumor cell lines. The phenolic derivatives exhibited the highest cytotoxicity among these derivatives, while the unsaturated esters were more cytotoxic than the saturated analogues. Some of the compounds also exhibited inhibition on α-glucosidase.
- Hu, Li Hong,Zou, Hong Bin,Gong, Jing Xu,Li, Hai Bo,Yang, Lei Xiang,Cheng, Wei,Zhou, Chang Xin,Bai, Hua,Gueritte, Francoise,Zhao, Yu
-
p. 342 - 348
(2007/10/03)
-