Table 3. Difference in Energy and Ratio (cis/trans) of Compounds 1a–p Calculated at mPW1PW91/6-311G(d,p), IEFPCM: CHCl3.
| compound | R1 | R2 | ΔGtrans/cis (kcal/mol) | trans/cis |
|---|---|---|---|---|
| 1a | –CH(CN)2 | –H | 2.57 | 99:1 |
| 1b | –CH(CN, CO2Et) | –H | 2.91 | 99:1 |
| 1c | –CH2CH3 | –H | 2.28 | 98:2 |
| 1d | –H | –H | 3.56 | >99:1 |
| 1e | –Br | –H | 2.09 | 97:3 |
| 1f | –CH3 | –H | 4.13 | >99:1 |
| 1g | –CO2CH2CH3 | –H | 2.67 | 99:1 |
| 1h | –H | 4′-Br | 3.51 | >99:1 |
| 1i | –H | 5′-Br | 3.60 | >99:1 |
| 1j | –H | 4′-OH | 2.40 | 98:2 |
| 1k | –H | 4′-F | 1.99 | 97:3 |
| 1l | –H | 4′,5′-F | 2.48 | 99:1 |
| 1m | –H | 5′-NO2 | 3.02 | 99:1 |
| 1n | –H | 4′-OCH3 | 1.75 | 95:5 |
| 1o | –CH3 | 4′-F | 2.95 | 99:1 |
| 1p | –Cl | 4′-F | 3.23 | >99:1 |