Synthesis of Trideca-O-methyl-alpha-pedunculagin. Diastereo-Favoritism Studies on Intramolecular Ester-Cyclization of Axially Chiral Diphenic Acids with Carbohydrate Core.
Total synthesis of trideca-O-methyl-alpha-pedunculagin was achieved by a simple sequence. The key step is the synthesis of methyl 4,6-O-benzylidene-2,3-O-[(S)-4,4',5,5',6,6'-hexamethoxydiphenoyl]-alpha-D-glucopyranoside through intramolecular ester-cyclization of racemic hexamethoxydiphenoyl chloride with methyl 4,6-O-benzylidene-alpha-D-glucopyranoside at the 2,3-position. The diastereoselectivity results obtained in the intramolecular cyclization of hexamethoxydiphenic acid to the carbohydrate core raises a very interesting point in considering the pathway of (R)-diphenic acid biosynthesis.
Itoh
Toshiyuki
T
Department of Chemistry, Faculty of Education and Faculty of Pharmaceutical Science, Okayama University, Okayama 700, Japan, and Department of Chemistry, Faculty of Science, Okayama University of Science, Okayama 700, Japan.
Chika Ji
Jun-ichi
Shirakami
Shohei
S
Ito
Hideyuki
H
Yoshida
Takashi
T
Kubo
Yuki
Y
Uenishi Ji
Jun-ichi