Multiple electrophilic aromatic substitution reactions of phloroglucinol and studies towards the total synthesis of hopeanol

An investigation of the triple electrophilic aromatic substitution (EAS) reactions of phloroglucinol (1,3,5-trihydroxybenzene) has led to the preparation of both symmetrical triple Mannich bases and structurally-complex polycyclic adducts. This research was based on two synthetic approaches that were developed separately for the total synthesis of the polycyclic and C3-symmetric natural product xyloketal A. The first systematic study led to the synthesis of a series of functionalized C3-symmetric dendrimer cores. In the second study, polycyclic analogues of xyloketal A were prepared via the triple EAS reactions of phloroglucinol with various carbon-based electrophiles. In addition, a novel C2-symmetric polycyclic quinone was isolated from the reaction of phloroglucinol with (+)-p-mentha-2-ene-1,8-diol. In a separate study, the total synthesis of the natural product hopeanol was undertaken. This involved the preparation of a 1,2-diketone precursor which was tested with an array of acid promoters in an attempt to complete this synthesis in a single synthetic operation.