Intra molecular hydrogen bonding in enol fo rm of ɑ-su bstitution of (Z) -۴, ۶-dioxo-۶-phenylhe x-۲-enoic acid [ZDP EA]

The cis- enol forms of ȕ-diketones are stabilized by a strong intram olecular hy drogen bond. This hydrogen bond formation l ead to an enhancement o f the resona nce conjug ation of the ʌ-electrons, which causes a marked tendency for equalization of the bond order of the valen ce bonds in the resulting six-member chelated ring. Theref ore, it seem s that any p arameter that effects th e electron d ensity of the chelated ring will change the hydrogen bond strength. It is well kno wn that substitution i n Į- or ȕ-p osition drastically changes the hy drogen bon d strength and the equilibrium bet ween keto an d enol tauto mers.

کلیدواژه ها:

Intramolecular hydro gen bonding ، ȕ-Dicarbo nyl ، Į-substitution ، (Z) -۴ ، ۶-dioxo-۶-phenylhex-۲-enoic acid