DETERMINATION OF ALKOXYLATION AND HYDROXYLATION SITES IN NATURALLY-OCCURRING PTEROCARPENES

A comparison of H-1-NMR of acetoxtypterocarpene and alkoxypterocarpene shows that the aromatic proton, para to the site of difference, under goes a larger change in chemical shift. When H-1-NMR spectra of acetox ypterocarpene and hydroxypterocarpene are compared, a similar trend is observed. In absence of a para-proton, ortho-protons undergo larger c hanges in chemical shifts. These changes in chemical shifts are helpfu l in locating alkoxylation and hydroxylation sites in naturally occurr ing pterocarpenes.