Synthesis of a new spiro organic peroxide is described. The peroxy bonds were incorporated into the substrate framework via an acid-catalyzed ketal exchange reaction using hydrogen peroxide as the source of peroxy linkage. The hydroperoxyl groups were then bonded at the OH ends via Hg(II)-induced electrophilic additions to the C-C double bonds, giving a novel sprio structure with one peroxy bond in each of the two six-membered rings. The ester functionalities in the side chains also make it possible to conduct further structural modifications.
Two aromatic hydrazide haptamers have been prepared,with both consisting of two hydrogen bonded folded segments. Compared to their fully hydrogen bonded analogues,the flexibility of their backbones increases due to lack of one or two intramolecular hydrogen bonds at the middle aromatic unit. (2D) 1H NMR,circular dichroism and fluorescent studies revealed that both oligomers moderately complex n-octyl-α-L-glucopyranoside in chloroform.
Three arylamide-bridged biscoumarin derivatives 1-3 have been designed and prepared. Compounds 1 and 2 are induced by the intramolecular N?H…O and N·H…F hydrogen bonding to possess a helical conformation,and 3 is induced to have an extended conformation. A comparison of their absorption and fluorescent spectra in a variety of solvents of a wide range of polarity with those of control compound 4 reveals that,for foldamers 1 and 2,the intramolecular hydrogen bonding and the helical conformations exist in most solvents,but do not exist or are very weak in DMF and DMSO.
LU ZhengQuanZHU YuanYuanLIN JianBinJIANG XiKuiLI ZhanTing