7. The optically pure tosylate of 2,2-dimethyl-1-phenyl-1-propanol ([α]D = -50°) was heated in acetic acid to yield the corresponding acetate ([α]D = +10°). If complete inversion had occurred, the optically pure acetate would have had [α]D = +50°. What percentage racemization occurred in this reaction? (A) 80% (B) 60% (C) 50% (D) 40% (E) 20%

4. trans-1-tert-Butyl-4-isopropylcyclohexane has two conformers. Using the following data to calculate the strain in this two conformers, by how much kJ/mol that one is favored than the other?If, H-C-C-H eclipsed interaction strain: 4 kJ/mol;CH3-C-C-H eclipsed interaction strain: 6 kJ/molCH3-C-C-CH3 eclipsed interaction strain: 11 kJ/mol;CH3-C-C-CH3 gauche interaction strain: 3.8 kJ/mol Each one strain (S) of 1, 3-X-H diaxial interaction in monosubstitutedcyclohexane (kJ/mol): (A) 9.2 (B) 22.8 (C) 32 (D) 16 (E) 11.4

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