Concomitant Addition and Acetalization of α,β-Unsaturated Aldehydes with Diols
نویسندگان
چکیده
During our investigation of the reduction of acrylic acid with lithium aluminum hydride, we observed several unidentified compounds. One of them seemed to be 2-vinyl1,3-dioxolane (3a), which is a widely known compound, but its formation under the reaction conditions was totally unexpected. In order to confirm the identity of the compound we attempted preparation of authentic compound of 3a from acrolein (1a) and ethylene glycol (2). However, the preparation of 3a by direct acetalization of 1a with 2 was not straightforward. Azeotropic treatment of 1a and 2 in benzene in the presence of H2SO4 as catalyst gave mostly a bisaddition product 4 in 33% yield and only a trace of the desired acetal 3 which was detected as shown in Scheme 1. The bis-adduct is a new compound to the best of our knowledge. We now report the reactions of α,β-unsaturated aldehydes with 1,2and 1,3-diols.
منابع مشابه
Chromium(II)-Catalyzed Diastereoselective Pinacol Type Cross Coupling between α,β-Unsaturated Carbonyl Compounds and Aliphatic Aldehydes
Synlett 2002, No. 12, Print: 02 12 2002. Art Id.1437-2096,E;2002,0,12,2015,2018,ftx,en;G26802ST.pdf. © Georg Thieme Verlag Stuttgart · New York ISSN 0936-5214 Abstract: Using only 10 mol% of CrCl2 as catalyst, acroleins and , -unsaturated ketones were coupled with aliphatic aldehydes to obtain substituted 1,2-diols using manganese powder as reducing agent and TMS-Cl as scavenger. Diastereoselec...
متن کاملMetal-Free Regiodivergent Addition of Carbon Nucleophiles to α,β-Unsaturated Electrophiles.
A mild and metal-free regiodivergent addition of carbon nucleophiles to α,β-unsaturated electrophiles was developed. Total 1,2-regioselectivity was observed in the addition of nitrobenzyl chloride derivative 1 to α,β-unsaturated aldehydes 2 in the presence of TDAE. Moreover, the reaction between p-nitrobenzyl chloride 1a and α,β-unsaturated iminium salts 4 led to the formation of the 1,4-adduct...
متن کاملUnderstanding α,β-unsaturated imine formation from amine additions to α,β-unsaturated aldehydes and ketones: an analytical and theoretical investigation.
A combination of in situ IR spectroscopy (ReactIR) and DFT calculations have been used to understand what factors govern the selectivity in the addition of primary amines to α,β-unsaturated aldehydes and ketones, i.e., 1,2- versus 1,4-addition. It has been found that the 1,2-addition products (α,β-unsaturated imines following addition and elimination) usually predominate for most systems. Howev...
متن کاملPeptide-catalyzed consecutive 1,6- and 1,4-additions of thiols to α,β,γ,δ-unsaturated aldehydes.
Regio- and enantioselective addition of thiols to α,β,γ,δ-unsaturated aldehydes was performed with a resin-supported peptide catalyst. It was shown that a 1,4-adduct was generated mainly at the initial stage of the reaction, and this was eventually converted to a thermodynamically stable 1,6- and 1,4-diadduct through retro-addition/addition reactions.
متن کاملStereoselective Synthesis, Synthetic and Pharmacological Application of Monoterpene-Based 1,2,4- and 1,3,4-Oxadiazoles
Stereoselective synthesis of monoterpene-based 1,2,4- and 1,3,4-oxadiazole derivatives was accomplished starting from α,β-unsaturated carboxylic acids, obtained by the oxidation of (-)-2-carene-3-aldehyde and commercially available (-)-myrtenal. 1,2,4-Oxadiazoles were prepared in two steps via the corresponding O-acylamidoxime intermediates, which then underwent cyclisation induced by tetrabuty...
متن کامل