Y. Habata et al., UNUSUAL MONOSUBSTITUTION-MONODECHLORINATION PRODUCT IN THE REACTION OF 1,8-DICHLOROANTHRAQUINONE WITH (S)-(-)-2-(TETRAHYDROPYRANYLOXY)-1-PROPANOL, Tetrahedron, 53(12), 1997, pp. 4179-4184
Treatment of 1,8-dichloroanthraquinone with (S)-(-)-2-(tetrahydropyran
yloxy)-1-propanol in the presence of NaH in THF gave monosubstitued-mo
nodechlorinated product 2 and desired 1,8-disubstitued product 1. Mole
cular mechanics calculations and H-1 NMR experiments suggest that the
tetrahydropyranyl group in the side chain of monosubstituted-monochlor
o product 3 hinders the second reaction site and the Na+ cation intera
cts with the oxygen atoms of the side chain and ketone function allowi
ng, the hydride anion access to the second reaction site. (C) 1997 Els
evier Science Ltd.