Dragojlovic, Veljko

Flosal (Jasmonal, Jasmine Aldehyde, (E)-2-benzylideneheptanal) is an important commercial fragrance compound. The principal method for its preparation involves a crossed aldol condensation reaction of heptanal and benzaldehyde. The method has a serious drawback as the synthesis of jasmine aldehyde is accompanied by self-condensation of heptanal to produce foul-smelling 2-pentyl-2-nonenal. We optimized the reaction conditions to maximize yield of jasmine aldehyde while preventing formation of 2-pentyl-2-nonenal. The desired product was obtained in ~60% yield, with a room for future improvement.

Oxidative cleavage of alkenes was carried out with catalytic ruthenium tetroxide in anhydrous t-butyl alcohol at room temperature. Mild conditions caused a slower and less exhaustive oxidation of the double bond so that aldehydes were the major reaction products.

The use of fluorous solvents in Diels-Alder reactions have been identified as a viable means to optimize the reaction’s stereoselectivity. Past research on the use of fluorous solvents in Diels-Alder reactions suggest that the characteristics of fluorous solvents (including their tendency to be both liphophobic and hydrophobic) may provide optimal conditions for Diels-Alder reactions. This study investigates these characteristics by comparing the effects of these solvents and other solvents (or the lack thereof) on the Diels-Alder reaction. The use of the fluorous solvent FC-70 was also studied for the purpose of cracking dicyclopentadiene. Literature on molecular interactions and on Diels Alder reactions is utilized to explain how the structural and chemical features of fluorous solvents influence reaction efficiency and selectivity, and how reaction conditions (heat and duration of reaction) alter the efficiency and selectivity. We use structural and thermodynamic arguments to explain these alterations. By better understanding how fluorous solvents function in Diels-Alder reactions, reaction conditions may be improved and their use expanded.

In organic synthesis, the phase-vanishing (PV) technique uses an organofluoride solution to keep two reactive solutions in separate layers, while allowing a reaction to
proceed at the interface of the fluorous layer. PV reactions allow otherwise vigorous
reactions to proceed at a slower, more controlled rate. In this research, we evaluated the use of PTFE tape as a phase screen in the synthesis of chiral α-halo ethers and acetals. We were successful in synthesizing the two compounds of interest, and also successful in their isolation through the use of column chromatography. Since α-halo ethers are known to be carcinogenic, the use of PTFE tape minimizes exposure to the potentially harmful substance.

The Phase-Vanishing polytetrafluoroethylene (PTFE, Teflon®) method separates two reactants with a layer of semipermeable polytetrafluoroethylene (PTFE, Teflon®) tape. Expanding on previous work by Van Zee and Dragojlovic, this work investigates the use of the PV-PTFE method under solvent-free conditions and explores its value as a synthetic method for Wittig reactions to produce allenes and allenyl esters. We conducted multiple brominations, halolactonizations, and tandem Diels-Alder-halolactonizations under solvent-free conditions with largely successful results. We also synthesized an allenyl ester, as well as cis-stilbenes using benzyltriphenylphosphonium salts, but cannot report any significant advantage of the PV-PTFE method over known methods.

Paraconic acids are naturally occurring compounds synthesized by bacteria and fungi. They are known for having antitumor and antibiotic properties. By use of a phasevanishing (PV) halolactonization with PTFE (Teflon) as a phase screen, we were able to synthesize precursors to these compounds. The PV-PTFE halolactonization of alkenoic acids with iodine monochloride gave the corresponding iodolactones, while
halolactonization with bromine gave the corresponding bromolactone. Halolactonization
of 4-pentenoic acid with water as a solvent also gave good results. Future experiments
will explore the synthesis of further precursors by means of a photolytic carbonylation of
iodolactone and a phenylation-ruthenium tetroxide oxidation sequence.

Chemistry lab work often mandates working with hazardous materials and this existing danger can be easily compounded by inexperience. Undergraduate and bachelors lab workers may be unfamiliar with aspects of lab safety and why certain safety recommendations are in place and the dangers involved. This work outlines safety practices that can be applied when working with air sensitive compounds and some of options that can affect safety procedures such as the type and material a syringe is made of.

FAU's Office of Undergraduate Research and Inquiry hosts an annual symposium where students engaged in undergraduate research may present their findings either through a poster presentation or an oral presentation.

FAU's Office of Undergraduate Research and Inquiry hosts an annual symposium where students engaged in undergraduate research may present their findings either through a poster presentation or an oral presentation.