Evans, Duffy, Ripin Conformational Barriers to Rotation: Olefin A-1, 3 Interactions Chem 206 2r-2-pentene (Z-2-buten-1-o/ § 0--s 180 -90 ΦqDeg) 180 ΦpDeg) 90 The Torsional Energy Profile The Torsional Energy Profile Φ=0 Φ=180 +3. 88 kcal Φ=180 Φ=90 +144 kcal Φ=120 kcal +0.52 alues calculated using MM2 (molecular mechanics)force fields via the Macromodel multiconformation search Review Hoffman. R. W. Chem. Rev. 1989. 89. 18410 1 2 3 4 5 -180 -90 0 90 180 0 1 2 3 4 5 -180 -90 0 90 180 Values calculated using MM2 (molecular mechanics) force fields via the Macromodel multiconformation search. Review: Hoffman, R. W. Chem. Rev. 1989, 89, 1841. (Z)-2-pentene (Z)-2-buten-1-ol (Deg) (Deg) Evans, Duffy, & Ripin Conformational Barriers to Rotation: Olefin A-1,3 Interactions Chem 206 E (kcal/mol) E (kcal/mol) +0.86 kcal +1.44 kcal F = 180 F = 120 F = 0 F = 0 F = 180 The Torsional Energy Profile The Torsional Energy Profile F = 0 F = 180 F = 0 F = 90 F = 180 +3.88 kcal +0.52 kcal H C Me C H H H H C Me Me H H C C H Me H H C Me C H H H OH C H H H HO OH H H C C H Me H OH Me H C Me C H H H Me Me H H C C H Me H H H C C H Me H F F