| dc.description.abstract | Fluorination is a typical strategy to greatly enhance a compound's chemical and
biological characteristics. In this project, Dipterocarpol lactone II, a dammarane type triterpenoid, was attempted to be fluorinated using iron (III) nitrate/NaBH4
and selectfluor. Based on the property of the fluorinating agent, the alkene
derivative IV acted as the reactant for the fluorination process. It was prepared
with good efficiency via elimination reaction of the lactone alcohol III. The highly
reactive radical intermediate resulted in many side reactions and by-products;
hence, different conditions were adjusted to control the reaction and focus on the
targeted products. Despite a number of spots emerging on the TLC plate of the
fluorination process, two major new spots, including FA and FB, were observed,
and presumed to be the reaction's main products. The two target products were
successfully purified, yet the yield was quite low. The 1
H NMR spectra of two newly
formed spots were obtained to initially verify the presence of fluorine in the
dipterocarpol backbone. Since no peak was observed in the region of 5-4 ppm in
the 1
H NMR spectrum of spot FB, the alkene IV was transformed into an alkane
derivative in which the C2-C3 double bond of IV was altered to a single bond. For
the isolated spot FA, it was presumed that there were two diastereomer products
formed in the fluorination reaction of compound IV according to two proton signals
appearing at 5.58 ppm and 4.91 ppm. In the presence of selectfluor and iron (III)
nitrate/NaBH4, a fluorine atom was presumed to be successfully attached to the
C-3 position of compound II. However, this was just an initial presumption based
on the 1
H NMR spectrum, it is suggested to further characterize the achieved
products to confirm assuredly the successful formation of a fluorinated derivative
of Dipterocarpol lactone II. | en_US |
