Table 1.

Results from the DFT calculations to estimate adduct formation energies and transition state barriers at the M06-2X/6-31(p,d) level (with SCRF=(IEFPCM,solvent=water)). S-cis conformation energies were reported except in the case of (49).

compound	Adduct formation energy (kcal/mol)	Transition state energy kcal/mol
56	−7.39	1.10
57	−12.04	3.21
49*	18.47	-
51	6.51	12.00
18	0.84	3.31
22	−4.46	2.29
28	9.30	9.96
36	−43.59	5.32
41	−2.40	2.14
45	−7.68	3.54
46	−2.42	6.06
44	−7.71	3.23
43	0.22	-
47	−10.43	2.12