Introduction
A reaction in organic chemistry that involves a simultaneous 3 pi bond shift is Diels-Alder cycloaddition, where a conjugated diene and an alkene with an electron withdrawing group (a dienophile) will react to form two carbon-carbon single bonds at the expense of the one carbon-carbon multiple bond to most often form a 6 membered ring adduct (Ketcha, 106). A conjugated diene is a hydrocarbon the contains two carbon-carbon double bonds and a dienophile also means “diene-loving” (Ketcha, 106).
There are two conditions for a cycloaddition reaction to occur. One is the carbon-carbon double bonds must be conjugated, and must also be in a cisoid form (Ketcha, 106). If a molecule is unable to shift into a cisoid, the reaction will not …show more content…
The flask was attached to a reflux condenser and the mixture was reflux for 45 minutes, during which butadiene sulfone was decomposed. The mixture was allowed to cool and then transfer to another 100 mL beak, with the addition of 10 mL of tetrahydrofuran. A small amount of charcoal was added to the solution, mixed, and vacuum filter. Hexanes (50 mL) were added to the filtrate, cooled in an ice bath, and vacuum filtrate once more. The precipitate was washed hexanes (15 mL) and dry on the filter (with vacuum) for 10 minutes. The product was weighed, percent yield calculated, dried on a clay plate, and melting point taken. An IR spectrum with KBr was taken using another group’s product as ours were not cooperating (the “window” was not staying intact, no matter what was …show more content…
Not sure exactly what happened, as other groups managed to get at least 30%, but could have been simply do to us not waiting long enough to for the mixture to solidified into crystals or something else entirely. Whatever the case may be, resulting product was just enough to determine its melting point, but not really enough to conduct an IR absorption spectrum, proven by the fact the “window” kept falling to pieces no matter what was done.
The melting point was 70-90 degrees C, meaning there were some impurities in the sample. These impurities might be shown in the IR spectrum.
An IR absorption spectrum was performed using another group’s sample. The IR had a peak at 3051 cm-1, from the alkene C-H stretch; at 2959 cm-1, 2905 cm-1, and 2852 cm-1 from the aliphatic C-H stretch; 1842 cm-1 and 1864 cm-1 from the asymmetric C=O stretch; 1775 cm-1 from the symmetric C=O stretch; 1696 cm-1 and 1657 cm-1 for the alkene C=C stretch; and multiple peaks between 999 cm-1 and 928 cm-1 from the out of plane C-H bond. These peaks closely match up to the expected peaks for 1,2,3,6-tetrahydrophthalic
A reaction in organic chemistry that involves a simultaneous 3 pi bond shift is Diels-Alder cycloaddition, where a conjugated diene and an alkene with an electron withdrawing group (a dienophile) will react to form two carbon-carbon single bonds at the expense of the one carbon-carbon multiple bond to most often form a 6 membered ring adduct (Ketcha, 106). A conjugated diene is a hydrocarbon the contains two carbon-carbon double bonds and a dienophile also means “diene-loving” (Ketcha, 106).
There are two conditions for a cycloaddition reaction to occur. One is the carbon-carbon double bonds must be conjugated, and must also be in a cisoid form (Ketcha, 106). If a molecule is unable to shift into a cisoid, the reaction will not …show more content…
The flask was attached to a reflux condenser and the mixture was reflux for 45 minutes, during which butadiene sulfone was decomposed. The mixture was allowed to cool and then transfer to another 100 mL beak, with the addition of 10 mL of tetrahydrofuran. A small amount of charcoal was added to the solution, mixed, and vacuum filter. Hexanes (50 mL) were added to the filtrate, cooled in an ice bath, and vacuum filtrate once more. The precipitate was washed hexanes (15 mL) and dry on the filter (with vacuum) for 10 minutes. The product was weighed, percent yield calculated, dried on a clay plate, and melting point taken. An IR spectrum with KBr was taken using another group’s product as ours were not cooperating (the “window” was not staying intact, no matter what was …show more content…
Not sure exactly what happened, as other groups managed to get at least 30%, but could have been simply do to us not waiting long enough to for the mixture to solidified into crystals or something else entirely. Whatever the case may be, resulting product was just enough to determine its melting point, but not really enough to conduct an IR absorption spectrum, proven by the fact the “window” kept falling to pieces no matter what was done.
The melting point was 70-90 degrees C, meaning there were some impurities in the sample. These impurities might be shown in the IR spectrum.
An IR absorption spectrum was performed using another group’s sample. The IR had a peak at 3051 cm-1, from the alkene C-H stretch; at 2959 cm-1, 2905 cm-1, and 2852 cm-1 from the aliphatic C-H stretch; 1842 cm-1 and 1864 cm-1 from the asymmetric C=O stretch; 1775 cm-1 from the symmetric C=O stretch; 1696 cm-1 and 1657 cm-1 for the alkene C=C stretch; and multiple peaks between 999 cm-1 and 928 cm-1 from the out of plane C-H bond. These peaks closely match up to the expected peaks for 1,2,3,6-tetrahydrophthalic