Artículos de revistas
Synthesis of methyl dihydrohardwickiate and its C-4 epimer. Structural amendment of natural crolechinic acid
Phytochemistry. Pergamon-elsevier Science Ltd, v. 53, n. 8, n. 851, n. 854, 2000.
Reduction of the alpha,beta-unsaturated ester moiety of (+)-methyl hardwickiate with magnesium in methanol afforded methyl (4aS,6S,8aS, 1R,5R)-5,6,8a-trimethyl-5-[2'-(3 '-oxoyl)-ethyl-perhydro-1-naphthalenyl]-carboxaylate, while reduction with sodium in n-propanol, followed by esterification with diazomethane, furnished its C-4 epimer. After comparison of thr H-1- and C-13-NMR data of these compounds with those reported for crolechinic acid isolated from Croton lechleri, a stereochemical revision for the natural product is suggested. (C) 2000 Elsevier Science Ltd. All rights reserved.538851854