TY - JOUR
AU1 - Surasani, Seshi Reddy
AU2 - Parumala, Santosh Kumar Reddy
AU3 - Peddinti, Rama Krishna
AB - The studies on [4 + 2] cycloaddition of 4-halo derivatives of 6,6-dimethoxycyclohexa-2,4-dienones known as orthoquinone monoketals/masked o-benzoquinones are described. The 4-fluoro, 4-chloro- and 4-iodo-masked o-benzoquinones were stable enough for their isolation and characterization. These conjugated dienones cycloadded with several electron-deficient and electron-rich dienophiles in a highly regio- and stereo-selective manner to afford the corresponding halo bicyclo[2.2.2]octenone derivatives in high to excellent chemical yields. The halo masked o-benzoquinones did not undergo dimerization under the reaction conditions. To evaluate the observed selectivities of these Diels–Alder reactions, we have performed quantum mechanical calculations for the reactions between halo masked o-benzoquinones and methyl vinyl ketone and ethyl vinyl ether at the B3LYP/6-31G** theory level. The differences in HOMO and LUMO energy gaps suggest that these reactions can be classified as inverse electron-demand Diels–Alder reactions. The calculated transition state energies and global electronic indexes supported the experimentally observed selectivities of the reaction in many cases.
TI - Diels–Alder reactions of 4-halo masked o-benzoquinones. Experimental and theoretical investigations
JF - Organic & Biomolecular Chemistry
DO - 10.1039/c4ob00856a
DA - 2014-07-08
UR - https://www.deepdyve.com/lp/royal-society-of-chemistry/diels-alder-reactions-of-4-halo-masked-o-benzoquinones-experimental-FD9kfiBm0Y
SP - 5656
EP - 5668
VL - 12
IS - 30
DP - DeepDyve
ER -