Steric Hyndrance Effects on Esters

A detailed Summary of Steric Hyndrance Effects on Esters

Electronegative and Steric Hindrance Effects on Synthesized Esters

Esters are made when an acid and an alcohol are mixed. The reaction causes the oxygen and hydrogen atoms to pair off, forming H20, leaving the rest of the compound to form the ester. The theory is that if a more electronegative element was added to the compound, it could increase the electronegativity in the whole molecule, and the ester could form more rapidly. The idea is that if you use a 3-bromo-1-propanol alcohol mixed with ethanoic acid, the bromine should create enough electronegativity so that the ester would form with more quantity and speed. This should effect the formation more than steric hindrance because the bromine is attached to the third carbon, hence all the movement from steric hindrance shouldn't cause bulkiness. Bromine is used because it is a very electronegative atom and should act as a catalyst by speeding up the reaction rate.

Synthesis of 3-bromopropyl acetate:

3- Bromo-1-propanol(11g, 117mmol) was added to two molar equivalents of ethanoic acid (13.992g, 233.2mmol). 3 drops of H2SO4 was added per every gram of the alcohol. It was refluxed for 30 minutes and allowed to cool over

propanol(12.2g, 203.3mmol) was added to two molar equivalents of ethanoic acid (25mL, 436.8mmol). 3 drops of H2SO4 was added per every gram of the alcohol. It was refluxed for 30 minutes and allowed to cool. The room temperature mixture was placed into a seperation funnel, where it was rinsed twice with distilled H2O, discarding as much of the aqueous layer as possible. It was then rinsed with 25 mL of NaHCO3 letting the pressure buildup escape at routine intervals until there was no more excessive pressure. This aqueous layer was tested with lithmus paper and was decided to be neutral. It was rinsed again with distilled H2O, and dried over 1-2g of MgSO4. The mixture was distilled and was discovered to have an 68.5% yield. Density of 0.8878(literature 0.887820/4), and a b.p. of 101.6ºC. NMR (CDCl3,300MgHz) δ 0.94463ppm (t,2H,CH2), 1.63991 (m,2H, CH2), 2.07838 (s,3H, CH3), 4.024 (t,2H,CH3).

2-methylbutanoic acid(10.19 g, 99.85 mmol) was added to 2 molar equivalents(12.14mL, 299.55mmol) of methanol. 3 drops of H2SO4 was added to the mixture, it was refluxed for 20 minutes and allowed to cool. The cooled mixture was placed in a separation funnel. It was then rinsed twice with 25 mL distilled H2O, with as much of the aqueous layer discarded as possible. The mixture was then rinsed using 20 mL NaHCO3, and the pressure routinely released. The aqueous layer was tested with litmus paper. Since it yielded a pH of 1, there was no need to repeat the NaHCO3. A 25 mL H2O rinse was done again. The mixture was dried over MgSO4. The mixtur

Some common words found in the essay are:
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Category: Science