Methyl acetate, molecular structure

Van Alsenoy, C., J. N. Scarsdale, and L. Schafer. 1982. Ab Initio Studies of Structural Features Not Easily Amenable to Experiment Part 24. Molecular structures and conformational analyses of the methyl esters of formic acid, acetic acid and alanine. J. Mol. Struct. (Theochem) 90, 297-304. 

The force-area curves for racemic and (5 )-(+>2-tetracosanyl acetate were shown in Figures 17 and 18, respectively, while those of methyl esters of racemic and (5 )-(+)-2-methylhexacosanoic acid are found in Figs. 21 and 22, respectively. All these curves were obtained under identical experimental conditions at thevarious temperatures indicated in the figures. Simple inspection shows that the force-area curves of the two racemic samples are very similar, as are those for both optically pure samples. Lundquist suggested that this is merely a result of the very similar shapes and molecular structures of these chiral surfactants. Apart from the chain length, the only structural difference is limited to a reversal of the positions of the carbonyl group and ester oxygen. 

Molecular structures of four choline esters and carbamic acid. Acetylcholine and methacholine are acetic acid esters of choline and 5-methyl choline, respectively. Carbachol and bethanechol are carbamic acid esters of the same alcohols. 

Figure 5.1. Molecular structures of the chemical repeat units for common polymers. Shown are (a) polyethylene (PE), (b) poly(vinyl chloride) (PVC), (c) polytetrafluoroethylene (PTFE), (d) polypropylene (PP), (e) polyisobutylene (PIB), (f) polybutadiene (PBD), (g) c/5-polyisoprene (natural rubber), (h) traw5-polychloroprene (Neoprene rubber), (i) polystyrene (PS), (j) poly(vinyl acetate) (PVAc), (k) poly(methyl methacrylate) (PMMA), ( ) polycaprolactam (polyamide - nylon 6), (m) nylon 6,6, (n) poly(ethylene teraphthalate), (o) poly(dimethyl siloxane) (PDMS).

C(3)-carbonyl group. A close approach to ideal boat geometry is observed in ring B of 3-methoxy-7a,8a-methyleneoestra-l,3,5(10)-trien-17)8-yl bromoacetate. Crystal and molecular structures are also reported for 16/8,17)8-dibromo-5a-androstane, 2a-bromo-17a-methyl-5a,14/S-androstan-3a-ol, esters of 3a,5a-cyclocholestan-6/3-ol, 4a,6,7a-trichloro-17a,21-dihydroxypregn-5-ene-3,l 1,20-trione 21 -acetate," 6a-bromo-17/8-hydroxy-17a-methyl-4-oxa-5a-androstan-3-... 

In a few instances solid polymers have been made by electric discharge from vinyl monomers which are commonly polymerized by other means. Thus, styrene (8,13,16), vinyl acetate (15), methyl methacrylate (8), and numerous alkenes have been polymerized by exposure to discharge. The products usually were compared with polymers made from the same monomers by conventional catalysis and the close similarity of infrared spectra was used as evidence for similar molecular structure. 

The nomenclature of esters is relatively simple, because it is similar to the nomenclature of salts. For instance, the ester obtained from methanol and ethanoic acid (acetic acid) is called methyl ethanoate (methyl acetate). Esters are compounds that comprise a large number of structures depending on what the alcohol and acid components are. Esters with a small molecular mass are volatile substances, in most cases with a pleasant odor. For instance, butyl acetate is responsible for the odor of apples. In nature, some esters serve as pheromones for insects, for example isoamyl acetate which attracts butterflies. Other kinds of esters can be large molecules as for instanee waxes and fats where both the alcohol and the acid components can be long-ehained or eomplicated structures. These natural esters will be diseussed in the ehapter on lipids. In industry, esters are used in the fabrication of polymeric fibers for textile materials and plastic materials for various uses. The most common material is polyethylene terephthalate (PET), the ester prepared from terephthalic acid and ethylene glycol. 

The molecular formula of methyl acetate is C3Hg02. Draw the structural formula of another ester with this same molecular formula. 

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