Acetaldehyde structural formula

Draw the structural formulae of the products from the aldol reaction of acetaldehyde and propiophenone and determine the configuration of the chirality centres. Assume that on the addition of base propiophenone attacks the acetaldehyde. 

Compare the structural formula of ethanol, acetate, and acetaldehyde. Which molecule is the most oxidized Which is the most reduced Explain your answers. 

How do we know that two - and not one or three - electrons are needed to reduce a molecule of acetaldehyde to ethanol Take a look at the structural formulas of acetaldehyde and ethanol. Fig. 9.9. What do you see The electrochemical reaction occurs on Cl. It changes its formal oxidation state, FOx(C), from -i-l in acetaldehyde to -1 in ethanol, that is, by two electrons. For a reminder how to assign a formal oxidation state to carbon atom take a look at Fig. 9.9. A +1 formal charge is assigned to each C-H bond, a —1 charge to carbon atom connected to O, N, Cl, or other electronegative atom. Finally, a zero is assigned to a C-C bond. 

Following are structural formulas and heats of combustion of acetaldehyde and ethylene oxide. Which of these compounds is more stable Explain. 

The condensed structural formula for acetaldehyde is CH3CHO. Its structural formula is... 

Here (H)R indicates a hydrocarbon group or H atom. The aldehyde function is usually abbreviated —CHO, and the structural formula of acetaldehyde is written CH3CHO. 

Pentaerythritol tetrallyl ether, 2 50 Pentaerythritol tetranitrate (PETN), 2 49 5 114. See also PETN molecular formula and structure, 5 110t Pentaerythrose, production from acetaldehyde, 1 104 Pentaethylenehexamines, physical properties, 8 486t... 

The conversion of a chemical with a given molecular formula to another compound with the same molecular formula but a different molecular structure, such as from a straight-chain to a branched-chain hydrocarbon or an alicyclic to an aromatic hydrocarbon. Examples include the isomerization of ethylene oxide to acetaldehyde (both C2H40) and butane to isobutane (both C4H10). 

A valuable hint for structure evaluation was that paspaclavine was cleaved in acidic medium to paliclavine and acetaldehyde while treatment of paliclavine with acetaldehyde yielded paspaclavine. A detailed spectroscopic analysis, especially of the NMR spectra, and some transformations finally led to formula 17 for paliclavine. Paspaclavine thus turned out to be a mixed O.A-acetal of paliclavine. The stereochemistry at C-7 was deduced from an examination of models. 

Treatment of ethyl acetoacetate with acetaldehyde in the presence of the base piperidine was found to give a product of formula Ci4H220<5. Controversy arose about its structure did it have open-chain structure III or cyclic structure IV, each formed by combinations of aldol and Michael condensations ... 

Draw a Lewis formula and a three-dimensional structure for each of the following polycentered molecules. Indicate hybridizations and bond angles at each carbon atom, (a) butane, C4H3Q (b) propene, H2C=CHCH3 (c) 1-butyne, HC=CCH2CH3 (d) acetaldehyde, CH3CHO. 

Carbothialdine" i.e. 4,6-dimethylperhydro-l,3,5-thiadiazine-2-thione, the reaction product of acetaldehyde with ammonia and carbon disulfide, has been known a long time (260, 288). Various structures have been proposed for it (83, 143, 164, 234). It was also known that this product may be obtained from acetaldehyde and ammonium dithiocarbamate and that two moles of aldehyde are necessary for the reaction. The reaction products of other aldehydes and amines had also been investigated with a view to elucidating their structure (31, 108). However, Ainley and co-workers (1) in 1944 were the first to determine the structure with certainty. The instability of "carbothialdines made it difficult to determine their structure by chemical means. It was by comparison of its U.V. spectrum with that of similar compounds such as (CCII) that the formula of perhydro-l,3,5-thiadiazine-2-thione (CCIV) was established, which accounts quite well for its properties. It is accepted... 

Figure 2 Topological, non-spatial representation of two isomers of formula C2 H4O, acetaldehyde (left) and ethylene oxide (right). Each number represents the number of covalent bonds linking the atom at the left of the row to the atom at the top of the column. All atoms of the molecule are listed both at the top and on the left-hand side. Each bond is only listed once, accounting for the half-filled appearance of the tables. These tables express all that was originally intended by the more conventional structure diagrams.

It is possible to decide between formula (1) on one hand and formulas (2) and (3) on the other from a consideration of the methods of formation of the two dibromoethanes. One of these compounds is formed when acetaldehyde is treated with phosphorus pentabromide. The structure of acetaldehyde has been shown by methods independent of this reaction to be represented by the following formula —... 

In the conversion of acetaldehyde into dibromoethane the simplest interpretation of the reaction leads to the view that the oxygen which it contains is replaced by two of the bromine atoms of the pentabromide, which is thereby converted into phosphorus oxybromide, POBrs its structure is, accordingly, that represented in formula (4) above. The dibromoethane formed in this way is not the one which results from the addition of bromine to ethylene this latter compound must, as a result, have the structure represented by formula (5) above, since formulas (4) and (5) represent all the possible configurations of a compound of the composition C2H4Br2. These facts exclude the possibility that ethylene has the structure represented by formula (1). 

There are two contributing resonance structures for an anion called acetaldehyde enolate, whose condensed molecular formula is CH2CHO . Draw the two resonance contributors and the resonance hybrid, then consider the map of electrostatic potential (MEP) shown below for this anion. Comment on whether the MEP is consistent or not with predominance of the resonance contributor you would have predicted to be represented most strongly in the hybrid. 

The structure of cocarboxylase (see Fig. 1 for formula) was established by Lohmann and Schuster. A long-established function of cocarboxylase (thiamine pyrophosphate, aneurin) is as the coenzyme of a-ketoaeid carboxylase. Mg++ is also required. The reaction involved is the nonoxidative decarboxylation of an a-keto acid to CO2 and an aldehyde with one less carbon atom. The most important example is the splitting of pyruvic acid to acetaldehyde and CO2 (equation 9). This... 

The reaction of two equivalents of Mg with 1,4-dibromobutane produces compound A. The reaction of A with two equivalents of CH3CHO (acetaldehyde), followed by work-up with dilute aqueous acid, produces compound B, having the formula CgHi802. What are the structures of A and B ... 

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