Ethylenedioxy unit

The highly reactive TT-bond of an indole nucleus can be protected by the addition of an ethylenedioxy unit. The adducts are formed in a reaction with ethanediol in the presence of PhI(OCOCF3)2. Reversion of the process is accomplished by NaBH3CN. ... 

A novel approach to the production of chiral, polymeric, crown ethers incorporating isomannide was developed by a Japanese group. The optically active divinyl ether 103 was polymerized with cationic catalysts to afford 104, consisting of only cyclic constitutional units.191 In addition, another crown ether (105), containing five ethylenedioxy moieties, was prepared. 

Compounds of the type RO—Y—OR, where the two parent compounds are identical and contain a group having priority over ethers for citation as suffix, are named as assemblies of identical units. For example, HOOC—CH2—O—CH2CH2—O—CH2—COOH is named 2,2 -(ethylenedioxy)diacetic acid. 

A number of naphtho[l,2-6]furan-6-ols, hetero-fused 1-naphthols, have been synthesised using the Stobbe condensation and converted into the furo[2,3-/]naphtho[l,2-6]pyran 54 by reaction with a propynol. Provided that an amino function is present in one of the 2,2-diaryl units, irradiation in toluene generates blue merocyanines, X,max 480 - 490 mn and 575 - 590 nm, which are strongly coloured and have half-lives of 30 - 60 s <03WOP025638>. The 8,9-methylenedioxy- and 8,9-ethylenedioxy-naphtho[l,2-6]pyrans have been obtained using the same methodology. They exhibit similar photochromic properties. 

The use of EDOT as basic units in poIy(heteroarylenemethines) has been achieved only recently. Thus, electrochemical oxidation of bis[2-(3,4-ethylenedioxy)thienyl]methane 31 led to poly(hisEDOT-methine) 32. The latter showed an electrochemical handgap of 0.4 eV based on the onset of oxidation and reduction waves while the determination of the optical handgap gave somewhat higher values [95]. Recently, the synthesis of poly(EDOT-methine) 33 was performed by the action of an excess of methanesulfonic acid on EDOT-carbaldehyde followed by the reduction of the resulting doped polymer. The related optical handgap was estimated to be around 0.95 eV [96]. 

Larmat, F., J.R. Reynolds, B.A. Reinhardt, L.L. Brott, and S.J. Clarson. 1997. Comparative reactivity of thiophene and 3,4-(ethylenedioxy)thiophene as terminal electropolymerizable units in bis-heterocycle arylenes. J Polym Set Part A Polym Chem 35 3627-3636. 

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