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Unformatted text preview: the solution might not have
completely recrystallized. If the vial was left on ice for a longer amount of time, more crystals
would’ve formed. A third area of product loss occurred when pouring the crystals and solution
onto the filter paper in the vacuum filter. Not all of the crystals escaped the vial when it was
emptied, even when rinsing it with 1 mL of petroleum ether, which reduced the yield. Another
area of product loss occurred when emptying the crystals from the filter paper to an aluminum
tray. Not all of the crystals were removed from the filter paper because they were stuck to the
paper’s surface. As much product as possible was scraped from the paper and onto the tray but
because the crystals were so small, not much product was obtained after all of the product loss
that occurred throughout the experiment.
The IR spectrometer was not working for our class therefore could not be used to
determine the purity of my specific product. The IR graph on Blackboard however shows a pure
sample of 4-cyclohexene-cis-1,2-carboxylic anhydride which is composed of a cyclohexene and
two carbonyl groups. The C=C group peaks on the graph at 3116.4 and the two C=O groups,
electron withdrawing groups, peak on the graph at 1770.3. The peaks on the Blackboard IR
graph are what our products should’ve looked like if they were pure and the IR spectrometer was
Diels-Alder Reaction Pre Lab:
2. It is important to avoid water in these reactions because in the presence of water both
maleic anhydride and butadiene sulfone are hydrolyzed. Maleic anhydride will react with
water to form maleic acid, which will not allow recrystallization of the product; the
reaction scheme is shown below in Figure 4.
Figure 4: Hydrolysis of Maleic Anhydride5 Wh en a cyclic a n h yd r id e, s u ch a s m a leic a n h yd r id e, is t h e d ien op h ile in
a Diels Ald er r ea ct ion , t h e p r od u ct is a ls o a n a n h yd r id e. H yd rolys is of t h e
a n h yd r id e oft en follows a s t h e n ext r ea ct ion in a s yn t h et ic s equ en ce. In s t ea d of h yd r oly...
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