Introduction
The purpose of this experiment was to convert carboxyl compounds into alkenes. While this reaction yields both the E and Z isomers, it is preferred over other reactions due to the lack of uncertainty of where the double bond is positioned. Also the stability of an ylide determines which isomer is the major product. 1
Experimental:
Compounds
Benzyltriphenylphosphonium chloride
9-Anthraldehyde
50% Aqueous NaOH
DCM
Product
Formula weight
388.87
206
N/A
N/A
280.36
Mole Ratio
1:1
1:1
N/A
N/A
1:1
Moles Needed
0.00064
0.000703
N/A
N/A
N/A
Quantity Needed
0.250 g
0.145 g
0.30 mL
1mL
0.395 g
Melting Point ( °C)
130-132 A white powder of Benzyltriphenylphosphonium chloride (0.255 …show more content…
The product was obtained in approximately 65.8% yield. We are confident that the synthesized product is trans-9-(2-Phenylethenyl)anthracene based on the obtained melting point as well as the experimental IR. The IR spectra had peaks at 3026 and 956 indicating a C-H stretch and trans alkene respectively. There is also a peak at 722 corresponding to an aromatic substitution. The experimental melting point range was measured at 128.7 °-131.9° which also consistent with the literatures melting point range at 130 °-132° for trans-9-(2-Phenylethenyl)anthracene. The TLC analysis furthermore corresponded with our results as it only showed one spot for the product indicating that it is in fact pure.3
References
1. Lindsay, Maria C., and Sean P. Hickey. "Wittig Reaction: Synthesis of trans-9-(2-Phenylethenyl)anthracene."Chem 3018 Organic Chemistry Lab 5. 2nd ed. Vol. 1. John Wiley and Sons, 2014. 19-28. Print.
2. Solomons, T. W. Graham. Organic Chemistry. 11th ed. New York: Wiley, 1992. Print.
3. Loffredo, William M. "Synthesis of Trans-9-(2-phenylethenyl)anthraldehyde: A Witting Reaction." (n.d.): n. pag. Synthesis of Trans-9-(2-phenylethenyl)anthraldehyde: A Witting Reaction. William M Loffredo, 11 Aug. 2004. Web. 2 Mar.