Chapter 7, Problem 2RT

It is not unexpected that the methoxyl substituent on a cyclohexane ring prefers to adopt the equatorial conformation. OMe H A G₂ = +0.6 kcal/mol OMe What is unexpected is that the closely related 2-methoxytetrahydropyran prefers the axial conformation: H H OMe OMe A Gp=-0.6 kcal/mol Methoxy: CH3O group Please be specific and clearly write the reason why this is observed. This effect that provides stabilization of the axial OCH 3 group in this molecule is called the anomeric effect. [Recall in the way of example, the staggered conformer of ethane is more stable than eclipsed owing to bonding MO interacting with anti-bonding MO...]

206 Pb 82 Express your answers as integers. Enter your answers separated by a comma. ▸ View Available Hint(s) VAΣ ΜΕ ΑΣΦ Np, N₁ = 82,126 Submit Previous Answers ? protons, neutrons

Please draw the inverted chair forms of the products for the two equilibrium reactions shown below. Circle the equilibrium reaction that would have a AG = 0, i.e., the relative energy of the reactant (to the left of the equilibrium arrows) equals the relative energy of the product? [No requirement to show or do calculations.] CH3 CH3 HH CH3 1 -CH3

5. Please consider the Newman projection of tartaric acid drawn below as an eclipsed conformer (1). Please draw the most stable conformer and two intermediate energy conformers noting that staggered conformers are lower in energy than eclipsed forms even if the staggered conformers have gauche relationships between groups. [Draw the substituents H and OH on the front carbons and H, OH and CO₂H on the back carbons based on staggered forms. -CO₂H is larger than -OH.] OH COH ICOOH COOH COOH 1 2 COOH COOH 3 4 Staggered Staggered Staggered (most stable) Indicate the number of each conformer above (1, 2, 3 and 4) that corresponds to the relative energies below. Ref=0 Rotation 6. (60 points) a. Are compounds 1 and 2 below enantiomers, diastereomers or identical? OH OH HO HO LOH HO HO OH 2 OH OH b. Please complete the zig-zag conformation of the compound (3R,4S)-3,4-dichloro-2,5-dimethylhexane by writing the respective atoms in the boxes. 3.

The plutonium isotope with 144 neutrons Enter the chemical symbol of the isotope.

The mass ratio of sodium to fluorine in sodium fluoride is 1.21:1. A sample of sodium fluoride produced 26.1 gg of sodium upon decomposition. How much fluorine was formed?

32S 16 Enter your answers numerically separated by a comma. Np. Nn = 跖 ΟΙ ΑΣΦ Submit Request Answer ? protons, neutrons

2. Which dimethylcyclohexane compounds shown below exhibit symmetry and therefore are not chiral and would not rotate plane polarized light. 1 CH3 CH CH3 CH3 2 3 CH3

Don't used hand raiting