(d) CH,C=C:- + CH¿CH¸OH

The two alternative chair conformations of cis-1-cyano-4-methylcyclohexane differ in their Gibbs free energy. Using the data for ΔG° for monosubstituted cyclohexanes at room temperature (25ºC): Axial → Equatorial Group ΔG° (kJ/mol) Group ΔG° (kJ/mol) C-N triple bond −0.8 NH2 −5.9 Br −2.4 CH3 −7.3 OH −3.9 1,2-gauche +3.8 calculate the absolute value of the difference in the Gibbs free energy between the alternative chair conformations.

Give the IUPAC name of the following compounds:

Consider the following equilibrium: O || R-C-H + HCN HO OH R-C-H | CN (A) When R = CH3CH2-, Keq = 1. (i) Predict whether Keq should be greater or less than 1 when R = CICH2, and (ii) when R is CH2=CH. Explain. (B) In the case where R is CH2=CH, the cyanohydrin is formed faster but given enough time, another constitutional isomeric C4H5NO product predominates. Explain and write a base-catalyzed mechanism for the formation of the other isomer. Recall that: HO HON N

H H T² CH₂ D A A

CH3 HC-C-OН CH3 1 H₂SO4 H3C H3C C=CH2 2 ?

For each organic compound in the table below, name the highlighted side chain. Note for advanced students: don't include the locant of the side chain. compound CH₂ - CH₂ - CH₂ - CH₂ I O CH₂ O || | || HO-C-CH-C-OH CH3 | CH₂=C- CH₂ CH₂ - CH₂ - CH₂ | O || CH=C=C=CH, CH₂ CH₂ CH₂ - CH₂ - - name of highlighted side chain 0

(s) (t) CH3-CH₂-C-OH OH + CH₂-CH₂-C- i NO₂ OH H₂ Pd/C H₂N A Heat NaNO₂ HCI HỌC—NH-CH3 B P₂O5, H₂O* Heat

Give the systematic name for each of the following; (b) (a) (d) CH3 I CH3-C-CH2-CH3 I CH3 CH3 CH3-CH2-CH-CH=CH2 CH3 I CH3-CH₂-CH-CH-CH3 I CH₂ I CH3 (e) (c) CH3 I CH3-CH₂-CH=C-CH-CH3 I CH3 -CH3 CH₂CH3

Identify the correct chair conformations of the following compound and then indicate which one is more stable. OH OH OH HO 1 || 4 OI and II are correct chair structures and I is most stable OI and II are correct chair structures and II is most stable OI and III are correct chair structures and III is most stable O II and III are correct chair structures and II is most stable O II and III are correct chair structures and III is most stable |||