Experiment 9 - Yield of each isomer in product mixture Ethyl 3-hydroxybutanoate Sample 10.05˚ Pure 43.76º ii Pure-43.76º Peak at 3529 2983

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Experiment #9 Yeast Reduction of Keto Esters April 22, 2009
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Balanced Reactions: Baker’s Yeast will be used as a chiral reducing medium to transform an achiral starting material, ethyl acetoacetate, into an achrial product, ethyl 3-hydroxybutanoate in an enantioselective process. i Mechanism: Results and Discussions: 1g of Baker’s yeast was added to 150ml of H20 and 1g of sucrose in stable 35degrees C environment. 3g of ethyl acetoacetate was added and the solution was stored until the next week. 5g of celite was then added to mixture, and the yeast and other solids were filtered way. The alcohol product was extracted twice with 30ml of diethyl ether, and then the diethyl ether was evaporated to obtain the product. Data: Observations Sample Optical Rotation IR Values
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Yield %ee % of each isomer in product mixture Ethyl 3-hydroxybutanoate Sample-+10.05˚ Pure (+) +43.76º ii Pure(-) -43.76º Peak at 3529, 2983, 2397, 1718, 1649 1.03g 23.9% (+)= 61.5% (-)= 38.5% IR Spectra: Attached Figure 1: ethyl acetoacetate Figure 2: ethyl 3-hydroxybutanoate Calculations: Conclusion: Optical Rotation predicts the solution contains 61.3% (S)-(+) ethyl 3-hydroxybutanoate and 38.5% (R)-(+) ethyl 3-hydroxybutanoate. Broad peak 3529 demonstrates –OH group, 2893 and 2937 are sp3 carbons, 1718 demonstrates ketone. Bibliography: i Courtesy of Chem. 2510 Experiment 9 Assignment ii i Ethyl 3-hydroxybutanoate MSDS <http://www.sigmaaldrich.com/catalog/ProductDetail.do?N4=W342807| ALDRICH&N5=SEARCH_CONCAT_PNO|BRAND_KEY&F=SPEC>...
View Full Document

This note was uploaded on 11/06/2010 for the course CHEM 2510 at Cornell University (Engineering School).

Page1 / 4

Experiment 9 - Yield of each isomer in product mixture Ethyl 3-hydroxybutanoate Sample 10.05˚ Pure 43.76º ii Pure-43.76º Peak at 3529 2983

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online