CHEMISTRY FINAL EXAMINATION Time 3 hr December 11, 2001

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1 Page 1 EMISTRY FINAL EXAMINATIN Time 3 hr December 11, 2001 NAME: ID #: READ ALL QUESTINS AND TE FLLWING INSTRUTINS AREFULLY AND ANSWER TE QUESTIN ASKED!! Answer all questions on the test paper. Extra sheets have been attached for rough work which will not be marked. nly the FIRST answer to any question will be considered. Point values for each question are given. There are 6 questions and 8 pages in this test and the available points total 100. No mechanisms are required unless specifically asked for. Any information provided which is not requested may still be marked! 1. Fill in the blanks with the structural formula required to complete the equation. Show any required catalysts over the arrow. Make sure your drawing shows stereochemistry if this is important. [36 points] a) ( ) 2 = ( ) 2 b) 2 2 ( ) 2 c) Mg 3 d) 3 N 3 e)

2 Page 2 f) g) h) 2 i). 2 Mg (excess) j) ( ) 2 2 k) ( ) Mg 2 l). 3 N 2

3 Page 3 2. (a) Draw the Newman projection of 3-ethoxycyclohexanecarboxylic acid in its less stable configuration and less stable chair conformation. Label the substituents as being axial (a) or equatorial (e). [note - ethoxy is bigger than the carboxy group] [4 points] (b) hoose the word (enantiomer, diastereomer, identical) which correctly describes the relationship between each of the following pairs of compounds. [3 points each] (i) 3 AND (ii) 3 AND

4 Page 4 (c) Draw the Fischer projection of 3-chlorohexane-2,4-diol in the 2R,3S,4S configuration [6 points] (d) Shown below are some stereochemical drawings. Provide an answer to the question asked about each one. [2 points each] (i) Draw the Fisher projection of the molecule which when mixed in a 1:1 ratio with the one shown will produce an optically inactive mixture.. 3 (ii) Draw the Fisher projection of a stereoisomer of the molecule shown that is a meso form. 3. (a) Draw the MPLETE MEANISM for the acid-catalyzed reaction of 3,3-dimethylbutanoic acid with excess methanol. Make sure you indicate which steps are reversible. ALS write the overall reaction and provide a valid IUPA name for the product. [8 points]

5 Page 5 (b) The acid-catalyzed reaction of 3-bromocyclohexene with water gives trans 2-bromocyclohexanol as the only product whereas the same reaction with 3-methylcyclohexene give a mixture of stereoisomers of both 2-methylcyclohexanol and 3-methylcyclohexanol. Explain the reason for this difference. [5 points] (c) [2 points each] You are given two bottles, each of which contains a pure chemical, and two labels. Explain how you would decide which label to attach to which bottle if the labels read: (i) 1-methylcyclohexanol and 2-methylcyclohexanol (ii) butanal and 3-butenal o (iii) water and 1-propanol (note- the boiling point of 1-propanol is 100 ) 4. (a) ne positional isomer of dimethylcyclohexane has more than one possible stereoisomer, NEITER F WI can be optically active. Which positional isomer is it and why can they not be optically active? [4 points]

6 Page 6 (b). 2 = N 3 N 3 2 = N 3 2 = 2 N 3 2 = 2 Which reaction will be more likely to proceed through a mechanism which has no intermediate and WY? [3 points] (c) Which reaction will NT give the indicated product and WY?? [4 points] 5. Show by equation how you could carry out any three of the following transformations, each of which may require up to three reactions. Show all reagents and the structures of each reaction product. [3 points each] (a)

7 Page 7 (b) 2 2 (c) (d) 2 6. Indicate whether the following statements are TRUE [T] or FALSE [F]. [1 point each]

8 Page 8 (a) The Tollen s test distinguishes between primary, secondary and tertiary alcohols [ ] (b) meso forms are always optically inactive. [ ] (c) Aldehydes are less reactive than esters in nucleophilic addition reactions [ ] (d) Amines are more nucleophilic than alcohols [ ] (e) Amides are more basic than amines [ ] RUG WRK PAGE (use both sides!!)

9 Page 9 appy olidays to all and best wishes for success in your future endeavours