Ellagitannin chemistry. Evolution of a three-component coupling strategy for the synthesis of the dimeric ellagitannin coriariin A and a dimeric gallotannin analogue.
The total synthesis of the dimeric ellagitannin coriariin A is reported. The key reaction to access the dimeric framework was realized early in the synthesis pathway via a bis acylation reaction of a dehydrodigalloyl diacid with 2 equiv of a glucopyranose trichloroacetimidate. The glucose rings were subsequently functionalized, culminating in a double oxidative cyclization to form stereoselectively both (S)-HHDP ester units. This bis acylation strategy was also employed to prepare a gallotannin analogue of coriariin A whose earlier synthesis by orthoquinone dimerization was plagued by yield-limiting side reactions.
Feldman
K S
KS
Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA. ksf@chem.psu.edu
Lawlor
M D
MD
Sahasrabudhe
K
K
D047348:Hydrolyzable Tannins / Q000031:analogs & derivatives / Q000138:chemical synthesis*; D013634:Tannins / Q000138:chemical synthesis*
D047348:Hydrolyzable Tannins; D013634:Tannins; C013515:ellagitannin