Synthesis and characterization of new aliphatic polyesters containing methanodinaphtho[1,3]dioxocin part

Abstract

A novel dinaphthodioxocin-containing diol monomer, 8,16-methano-16H-dinaphtho[2,1-d:1 0 ,2 0 -g][1,3] dioxocin-2,14-diol (MDDD) was synthesized in high yield and purity through the condensation of 2,7-dihydroxynaphthalene with malonaldehydetetramethyl acetal at room temperature. It is used as a new monomer for the synthesis of a series of novel dinaphthodioxocin-containing aliphatic polyesters by interfacial polycondensation method. The new diol monomer was fully characterized by IR, NMR, mass spectroscopies, and elemental analysis. Optimal conditions for polyesterification were obtained via study of the model compounds. Polyesters derived from MDDD and four aliphatic diacid chlorides had inherent viscosities ranging from 0.26 to 0.38 dL/g. The chemical structure of the polymers was fully characterized by IR, NMR spectroscopies, and elemental analysis. The physical properties of the polymers were studied. All the new polymers show good thermal stability and very good solubility in most organic solvents.

Synthesis of A-Type Proanthocyanidins and Their Analogues: A Comprehensive Review

“…Other starting materials have also been used to achieve the synthesis of 2,8-dioxabicyclo[3.3.1]­nonane derivatives, such as β-dicarbonylic compounds, − chromenes, − and arylpropinals (Figure ). The first substrates (1,3-dicarbonylic compounds) have been used by different research groups (Scheme ) following similar experimental procedures: a mixture of two equivalents of the phenolic compound (usually naphtol or phenol) and one equivalent of the proper dicarbonylic compound (malonaldehyde, β-ketoaldehydes, , or malonaldehyde tetraacetal − ) were reacted in the presence of Brønsted acids to afford the symmetric bicycle 73 in moderate to high yields (60–82%) (Scheme ).…”

“… a Reagents and conditions: (a) malonaldehyde, HCOOH, 60 °C, 4 h; (b) β-ketoaldehyde, HOAc, H 2 SO 4 , 50 °C, 12 h; , and (c) malonaldehyde tetraacetal, trifluoroacetic acid, rt, 48 h. − …”

Polystyrene-supported GaCl3 as a highly efficient and recyclable heterogeneous Lewis acid catalyst for one-pot synthesis of N-substituted pyrroles

“…As part of our continuing interest in heterogeneously catalyzed organic reactions [35,36], we report herein an efficient and eco-friendly procedure for the synthesis of pyrroles from 2,5-hexanedione and primary amines catalyzed by polystyrenesupported GaCl 3 as a reusable heterogeneous Lewis acid catalyst (Scheme 1). To the best of our knowledge, this is only second example of PS/GaCl 3 as a catalyst for any organic transformation.…”

One-pot synthesis of novel ladder type condensation polymers via condensation reactions of dihydroxyaromatic compounds and 2,5-dimethoxytetrahydrofuran

“…Recently, we successfully prepared a series of polymer forming monomers having suitable functional groups starting from condensation of p-substituted phenols with glyoxal, which can be used as important monomers for the preparation of a variety of thermally stable polymers [28]. In continuation of our interest in synthesis of organic compounds from condensation of phenols with dialdehydes, especially, 2,5-dimethoxytetrahydrofuran as a protected 1,4-dicarbonyl compound [22,[27][28][29] and our ongoing research on the efficient and convenient procedure for the synthesis of condensation polymers (ladder type polymers) by the reaction of dihydroxyaromatic compounds with dialdehydes [30], herein we now report an efficient and convenient procedure for the synthesis of new condensation polymers (ladder type polymers), having heterocyclic rings in the chain by a one-pot condensation reactions of dihydroxyaromatic compounds (para-substituted) with 2,5-dimethoxytetrahydrofuran as a protected dialdehyde using trifluoroacetic acid at room temperature in high yields.…”