Synthesis and Absolute Configuration of Two Natural Phenolic Homobenzyl Esters

Article abstract of DOI:10.1002/cjoc.201500315

Two recently identified natural phenolic homobenzyl esters, isolated from Phragmipedium calurum (an orchid) and Eupatorium fortunei TURCZ (a perennial herb in the Asteraceae family), respectively, were synthesized in enantiopure forms. By comparison of the optical rotations for the synthetic and the natural samples, the absolute configurations for the natural products were reliably assigned. The synthesis also enables establishment of the absolute configuration of a closely related natural homobenzyl alcohol and provided for the first time complete physical and spectroscopic data for two other natural homobenzyl esters. Two recently isolated natural phenolic homobenzyl esters were synthesized in enantiopure forms. The absolute configurations for these natural products were thus reliably assigned. En route to the total synthesis of the first target, complete physical and spectroscopic data for two other related natural products were made available for the first time. Configuration assignment of a third natural product was also achieved.