The First Total Synthesis of Praecoxin B and Pterocarinin C, Two Natural Products of the Tannin Class

Abstract

Abstract Enantiomerically pure diphenic ester 3 was obtained by esterification of acyl chloride 2 with the glucose derivative 1 by kinetic resolution. Hydrolysis of the ester 3 , acylation of the free OH groups at C‐4 and C‐6 of the diol 4 with acid 5 followed by irradiation led to the anomerically deprotected α‐ and β‐anomers ( 7 ) (4:1). The natural product praecoxin B ( 8 ) was obtained by hydrogenative debenzylation. A second member of the ellagitannin group pterocarinin C ( 11 ) was obtained from the common intermediate 7 by acylation in the anomeric position to 10 followed by debenzylation.