Wade 7th Ed. (2009)
CH 5: Stereochemistry

Solutions can be seen at mendelset.com/chapters/1023


  1. Problem # 319

    For a molecule to undergo an E2 reaction, the leaving group and the beta-proton must be in an anti-coplanar conformation (one atom straight up, the other straight down). Based on this, which compound undergoes E2 reaction with KOtBu faster? Why?

     

  2. Problem # 525

    On the molecule below, mark each stereocenter with an asterisk. (Note: in some textbooks, stereocenters are referred to as stereogenic centers, chirality centers, or asymmetric centers).

  3. Problem # 526

    Assign R or S configuration for each molecule below.

    a) is straightforward. I've started you off in b).

  4. Problem # 527

    Draw the structure of (2R,3S) 2-bromo-3-chlorobutane using wedges and dashes. Also draw a Fischer projection.

  5. Problem # 528

    Indicate which of the molecules below are chiral (if any).

  6. Problem # 529

    Indicate the major organic product of the reaction below. Include stereochemistry.

  7. Problem # 530

     

    Let's work through anti and syn additions to alkenes.
    Show the product for each reaction below, and indicate whether the product will be a racemic mixture of enantiomers, or a meso compound (which is achiral).

  8. Problem # 531

     

    E2 elimination reactions require anti-coplanar geometry. (note: some textbooks call this anti-periplanar).
    Let's work through an E2 reaction, and rotate the molecule eblow into an anti-coplanar geometry to predict the product of this E2 reaction.

     

  9. Problem # 532

    Let's work through a chiral resolution. Write out the structure of the indicated compound in each box. Include stereochemistry.

    Why is it possible to separate the (R,R) and (R,S) salts?

  10. Problem # 744

    After a sample of optically pure (S)-2-ethyl-cyclohexanone is dissolved in an aqueous solution for several hours, a significant loss of optical activity is observed. Explain.