A bioinspired approach for construction of the [7-5-6-5] all-carbon tetracyclic core of logeracemin A

Abstract

An efficient synthetic approach for the spiro-linked [7-5-6-5] all-carbon tetracyclic core derivatives of logeracemin A, a unique dimeric calyciphylline A-type alkaloid, from the known methyl cyclohept-1-ene carboxylate was described. The synthesis features a bioinspired successive Michael/double aldol/dehydration reaction sequence, which might indicate the possibility of a more efficient alternative biosynthetic pathway of logeracemin A.