Wittig Reaction Lab Report

Many sources of error were responsible for recovering a small amount of product. Introduction: The carbon-carbon bond formation is an important tool in organic chemistry to construct the simple as well as an organic compound. There are several

The percent yield was calculated to be 129.7%. This high percent yield resulted from the presence of

Tyler White CHEM151LL 32658 04/01/2018 Different Types Chemical Reaction Types and Equations Purpose: The purpose of this lab experiment is to examine different types of chemical reactions such as Decomposition reaction, Synthesis reactions, Combustion reactions, and different Chemical equations. The experiments were conducted online using Late Nite Labs. Materials: Because the experiments were conducted online there wasn’t any physical use of materials, only digital ones, for these labs to be performed. Only the registration for the website was needed to perform these online labs, as well as a desktop computer.

Introduction Tyrosinase is a copper-containing enzyme that catalyzes oxidation steps in melanin synthesis (Curto, et al.) Tyrosinase and its inhibitors have been studied for cosmetic and medical purposes. By inhibiting tyrosinase activity, skin can be whitened for cosmetic purposes. Inhibiting tyrosinase activity can also be a treatment for disorders involving elevated pigmentation of the skin such as age spots (Heng). Tyrosinase is active between a pH of 6.0 and 7.8.

Vacuum filtration was performed on the crude product, then it was recrystallized for purification. Melting point analysis was conducted on the recrystallized product to determine its identity. 3. The three possible mechanisms in this experiment were syn-addition

As seen in table 1, the theoretical yield was .712 g of C_17 H_19 NO_3. The % yield of this experiment was 7.51 % of C_17 H_19 NO_3. . This low yield can be explained from a poor recrystallization technique combined with potential contamination. Throughout the experiment, the mixture changed color from green, orange, to yellowish lime, and eventually clear.

In this lab there were five different stations. For the first station we had to determine an unknown mass and the percent difference. To find the unknown mass we set up the equation Fleft*dleft = Fright*dright. We then substituted in the values (26.05 N * 41cm = 34cm * x N) and solved for Fright to get (320.5g). To determine the percent difference we used the formula Abs[((Value 1 - Value 2) / average of 1 & 2) * 100], substituted the values (Abs[((320.5 - 315.8) /

So these would tend to have more reflections building up, to see that the biggest buildup is in the 400Hz band gives an idea how these materials can influence each other to resonate at a lower range than the previous

In This reaction dimethyl acetylenedicarboxylate was used as the dienophile with a Carbonyl group as the electron-withdrawing group. A resonance stabilized aromatic ring was formed ( favored rection). The nitrobenzene was used to facilitate the by acting as a high boiling solvent, dissolving both reactants, and thereby driving the Diels-Alder reaction. Refluxing moved this reaction further, forming an intermediate. The violet solution turned beige when forming a six-membered ring by losing carbon monoxide.

While under the UV light the mixtures appeared a purple colour. The R_fValue Starting material: R_F=2.6/4.5 = 0.58 The sum: R_F=2.55/4.5 = 0.57

The objective of this experiment was to use an aldol condensation reaction to synthesize 3-nitrochalcone from 3- nitrobenzaldehyde. This was accomplished with a Diels-Alder reaction that utilized 3-nitrobenzaldehyde, acetophenone, ethanol, and sodium hydroxide. The mechanism for the synthesis of 3-nitrochalcone is presented in Figures 1 and 2. The alpha carbon on the acetophenone is deprotonated. This is followed by the attack of the alpha carbon anion on the carbonyl carbon on the 3-nitrobenzaldehyde.

The experimental melting point was calculated to be 159.0-159.6°C, which is very accurate compared to the actual melting range of 160-163°C. The percent yield came out to be 26.89%, which is low but is consistent with other in the class due to the difficult nature of forming the trimethylmethanol crystals. Overall, this was a successful experiment because in the end there was a decent amount of pure crystal product. Questions 1.

(150.22g/mol)(3.5 x 10^-3 mol of nucleophile) = 0.525 g Actual yield = 0.441 g, Percent Yield = (0.441g/0.525g) x 100% = 84% 10. Percent recovery from recrystallization = (0.172g/0.441g) x 100% = 38% 11.

This supports the isolated product is majority made of the desired product and is largely pure. Mass spectrometry of the crude product shows the molecular ion peak is 162.1, which is the largest fragment in the mass spectrum (Figure 4) and corresponds to the molecular weight of methyl trans-cinnamate (Table 1). The base peak is 131, inferring the fragment lost is 31 m/z in size. This 31 m/z matches the OCH3 fragment of the ester, and would not result from a trans-cinnamic acid. This is evidence the product was successfully

The actual data is the result on our experiment vs theoretical, which is based on the calculations above. I have also learned to pay more attention to draining out all of the product completely before continuing to test the experiment, as any small drop of contaminant can veer our results into a different