In each of the following sets, which structures represent the same com- pound and which represent different compounds? (а) Br CH3 CH3 CH3CHCHCH3 CH3CHCHCH3 CH3CHCHCH3 CH3 Br Br (b) но. но. HO HO он HO (c) CH3 CH2CH3 CH3 CH3 CH,CH,CHCH,CHCH, HOCH,CHCH,CHCH, CH,CH,CHCH,CHCH,0H HOCH2CHCH2CHCH3 CH3CH2CHCH2CHCH2OH CH2OH CH3

Which of the following compounds are identical? H H3C- OH H- HO- CH3 OH H3C- H- НО CH3 H H H3C- Но CH3 CH3 H HO CH3 H3C- H- OH

Give the IUPAC name of the following: a, b, c, d, e, f

please answer

15) Which of the following structures is correct for 1,2-dibromo-2-methyl butane? CH₂-CH-CH₂Br Br CH₂CH₂-CH-CH₂ CH₂CH₂Br CH₂ A) C) CH₂CH3 BrCH₂-C-Br CH₂ B) D) BrCH₂-CH-CHCH₂ 1 Br CH₂

Compounds 1 and 2 were prepared, and the difference in their heats of combustion was found to be 17.2 kJ/mol (J. Am. Chem. Soc. 1961, 83, 606-614): H H 1 Shown below are the lowest-energy conformations of compounds 1 and 2. Identify which drawing matches which compound, and identify which compound has the larger heat of combustion. H H H H |||I 2 H 4 H H The first drawing is compound 1, and compound 1 has a larger heat of combustion because it is the less stable compound. O The first drawing is compound 2, and compound 2 has a larger heat of combustion because it is the less stable compound. The first drawing is compound 2, and compound 2 has a larger heat of combustion because it is the more stable compound. The first drawing is compound 1, and compound 1 has a larger heat of combustion because it is the more stable compound.

The questions are on the image

Q22. (A) Write IUPAC names for the following compounds: A2.5 H₂C, CH₁ OH H,C-CH₂-CH-CH-CH₂-CH-CH₂-CH, L H₂C-CH-CH, CH, CH CH₂ T C C-CH-CH₂-CH₂ CH₁ CH₂ CH₂CH₂CHCHCH₂ OH O OH

Given the structures of the following two tetramethylcyclohexanes: CH3 CH3 CH3 "CH3 CH3 CH3 A В (a) Draw the most stable chair conformation for both A and B. Which structure is lower in energy (most stable)? (b) Ring flip the above structures and draw the least stable chair conformation for both A and B. Which structure is highest in energy (least stable)?

3-44 Draw the two chair conformations of each compound and label the substituents as axial and equatorial. In each case, deter- mine which conformation is more stable. (a) cis-1-ethyl-2-isopropylcyclohexane (c) cis-1-ethyl-3-methylcyclohexane (e) cis-1-ethyl-4-methylcyclohexane (d) (b) trans-1-ethyl-2-isopropylcyclohexane trans-1-ethyl-3-methylcyclohexane trans-1-ethyl-4-methylcyclohexane (f)