Chem239A, Exam#3 - (c) Draw a Fisher projection of L-allose...

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CHEM 239A Summer, 2009 EXAM #3 Name . Prof. Sasaki 150 points TOTAL Good Luck! Note: Only answers in the box will be graded. _______________________________________________________________________ 1. (40) (a) Suggest a reasonable mechanism for the following reaction. Cl NCH 2 CH 2 NHCH 3 CH 3 NaNH 2 dietheyl ether N N H 3 C H 3 C (b) Treatment of 2,4,6-tribromophenol with excess aqueous potassium bromide gives 2,4,4,6-tetrabromocyclohexadienenone. Provide a reasonable mechanism. O Br Br Br Br 2,4,4,6-tetrabromocyclohexadienone
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CHEM 239A page 2 Name . 2. (40) The following structure is an unconventional representation of a chair conformation of a cyclic hemiacetal form of D-allose. Answer the following questions. O HO OH H H H OH H OH H HO (a) Circle the anomeric carbon in the structure above, and assign α or β configuration. (b) Draw the Haworth formula of the hemiacetal form of D-allose.
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Unformatted text preview: (c) Draw a Fisher projection of L-allose (note: not D-allose). (d) Draw the Haworth formula of Ethyl-2-deoxy-D--allopyranoside. CHEM 239A page 3 Name . 3. (40) Draw a reasonable mechanism for the formation of methyl glycoside of fructose in an acidic condition. Use curved arrows to indicate the movement of electrons. CH 2 OH C=O H HO OH H OH H CH 2 OH fructose CH 3 OH H + (catalysis) O HO OH OH OCH 3 OH CHEM 239A page 4 Name . 4. (35) (a) Predict the major product(s) for each of the following reactions. If more than one product is expected, please put all of them in the box. (a) Cl Cl 1) HNO 3 , H 2 SO 4 , 120C 2) NH 3 , ethylene glycol, 140 C C 6 H 6 N 4 O 4 (b) OH Cl Cl Cl + C 6 H 5 N N Cl (c) OH CO 2 , heat NaOH (d) H 3 C CH CH 3 CH 3 O O CH 3 AlCl 3 (e) OH NH O OH O water 125 I 2 acetyl tyrosine...
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This note was uploaded on 01/19/2012 for the course CHEM 239 taught by Professor Sasaki during the Summer '06 term at University of Washington.

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Chem239A, Exam#3 - (c) Draw a Fisher projection of L-allose...

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