Question

Of the following compounds, how many could not react (as a diene) in a Diels-Alder reaction? 1 2 O 4 O

Answer 1

answer s

1) option c (3 compound)

2)option c

3) option a (2 aromatic)

XX Х In diels aldol reaction the diene shoud be conjugated he diene component must be able to assume a s-cis conformation. in the above compoiunds 2 compounds will acts as diene. remining 3 compounds are not act as diene for diels alder reaction the anion also paricipating resonce, total 6 pi electons 3 bonding orbitals aromatic compounds have follow the huckel rule (4n+2) pi electons, and the compoud shoud be planar + aromatic aromatic follow 4n+2 rule, here n = 0 6 pi electrons follow 4n+2 rule, here n = 2 anti aromatic anti aromatic 4 pi electrons 4n+2 rule not follow lone pair on N not participating in resonance 8 pi electrons, not following 4n+2 rule the lone pair on oxygen will participate in resonance NH2 non aromatic anti aromatic 4 pi electrons 4n+2 rule not follow Ino one pair on N to participating in resonance cyclooctatetraene in not planar, 8 pi electons not follow 4n+2 rule