Propionate, structure

Therapeutic Function Cancer chemotherapy Chemical Name 2a-Methyl-17 5-(l-oxopropoxy)-5a-androstan-3-one Common Name 2-Methyldihydrotestosterone propionate Structural Formula ... 

Common Name Fluticasone propionate Structural Formula ... 

The ester and catalj st are usually employed in equimoleciilar amounts. With R =CjHs (phenyl propionate), the products are o- and p-propiophenol with R = CH3 (phenyl acetate), o- and p-hydroxyacetophenone are formed. The nature of the product is influenced by the structure of the ester, by the temperature, the solvent and the amount of aluminium chloride used generally, low reaction temperatures favour the formation of p-hydroxy ketones. It is usually possible to separate the two hydroxy ketones by fractional distillation under diminished pressure through an efficient fractionating column or by steam distillation the ortho compounds, being chelated, are more volatile in steam It may be mentioned that Clemmensen reduction (compare Section IV,6) of the hj droxy ketones affords an excellent route to the substituted phenols. 

Display electrostatic potential maps for the conjugate bases of the acids above (hydroxide, ethoxide, formate and propionate anions), and examine the value of the electrostatic potential at the most electron-rich site. What causes a larger change in electrostatic potential, switching the alkyl group for H, or changing the structure of the functional group ... 

The ratio of products 15 and 16 is dependent on the structures, base, and the solvent. The kinetics of the reaction is likewise dependant on the structures and conditions of the reaction. Thus addition or cyclization can be the rate-determining step. In a particularly noteworthy study by Zimmerman and Ahramjian, it was reported that when both diastereomers of 20 were treated individually with potassium r-butoxide only as-epoxy propionate 21 was isolated. It is postulated that the cyclization is the rate-limiting step. Thus, for these substrates, the retro-aldolization/aldolization step reversible. ... 

Therapeutic Function Antiinflammatory Chemical Name 3-(4-Biphenylylcarbonyl)propionic acid Common Name -Structural Formula ... 

Chemical Name (+)-6-methoxy-a-methyl-2-naphthaleneacetic acid Common Name d-2-(6-methoxy-2-naphthyl)propionic acid Structural Formula ... 

Acetylated polysaccharides form part of the structure of wood, the acetyl radical constituting some 2-5Vo by weight of the dry wood. Hydrolysis to free acetic acid occurs in the presence of moisture at a rate varying from one species to another a wood of lower acetyl content can liberate acetic acid much faster under given conditions than another wood of higher content Small quantities of formic, propionic and butyric acids are also formed but their effects can be neglected in comparison with those of acetic acid. There is a broad, but only a broad, correlation between the corrosivity of a wood and its acidity. The chemistry of acetyl linkage in wood and of its hydrolysis has been examined in some detail. ... 

There is a compound called propanol with structural formula CH3CH2CH2OH. If it is oxidized carefully, an aldehyde called propionaldehyde is obtained. Vigorous oxidation gives an acid called propionic acid. Draw structural formulas like those shown in Figures 18-6 and 18-7 for propionaldehyde and propionic acid. 

Antihistamines are drags used to counteract the effects of histamine on body organs and structures. Examples of antihistamines include diphenhydramine (Benadryl), loratadine (Claritin), fexofenadine (Allegra), and cetirizine (Zyrtec). A new antihistamine, deslorata-dine (Clarinex), is die active metabolite of loratadine and is intended to eventually replace loratadine (Claritin). Topical corticosteroid nasal sprays such as fluticasone propionate (Flonase) or triamcinolone ace-tonide (Nasacort AQ) are also used for nasal allergy symptoms. See Chapter 56 for more information on die topical corticosteroids. 

In a related series of experiments, the amino group and/or the carboxylic acid group of tyrosine were replaced by hydrogen atoms. The corresponding tyrosine derivatives are 3-(4 -hydroxyphenyl)-propionic acid, commonly known as desaminotyrosine (Dat), and tyramine (Tym) (structures 3-5). 

Figure 32-13. Structure of bilirubin diglucuronide (conjugated, "direct-reacting" bilirubin). Glucuronic acid is attached via ester linkage to the two propionic acid groups of bilirubin to form an acylglucuronide.

The structures of the acetic acidS0) and of the propionic acid71 inclusions of 26 (Fig. 20, type III) are isomorphous to each other. The increased guest volume with respect to formic acid yields 1 1 stoichiometry, with no H-bonds between host and guest molecules in either case. The tunnel where the dimers of guests are situated (see Fig. 32 a) is functionally the same as in the case of the self-dimerized pairs of the formic acid guests. 

There are two different oligomer series present in all spectra. The oligomer series can be identified by calculating the masses of the end groups and assigning them to specific chemical structures (Pasch and Schrepp, 2003 Weidner et al., 2004). In the present example, the two species are the propionic amide-acid (R-am-ac) and the propionic amide-propionic amide polyamides (R-am-am-R). The use of MALDI-TOF MS as a structure-sensitive detector allows the resolution to be indirectly enhanced since several species coelute, as shown in Fig. 17.21. The polarity of the... 

TMS is not ideally suited for use in all solvents, however. As you can see from the structure, it is extremely nonpolar and so tends to evaporate from the more polar solvents (D6-DMSO and D4-MeOD). For this reason, a more polar derivative of TMS [3-(Trimethylsilyl) propionic-2,2,3,3-D4 acid TSP -see Structure 2.2] is often used with these solvents. 

Structure 2.2 3-(Trimethylsilyl) propionic-2,2,3,3-D4 acid, sodium salt. 

The study above does not account for the extra six carbons acquired in the conversion of piperideine (8, 10 carbons) to phlegmarine (9, 16 carbons). It was initially proposed that the carbons were incorporated via pelletierine (12), which was incorporated twice into lycopodine resulting in two symmetrical halves of the alkaloid (Scheme 6.2). However, when 14C-labeled pelletierine (12, label at C2) was fed to the plant, degradation studies of lycopodine revealed that only one half consisted of the 14C label from pelletierine (the half containing C9-C16) [10]. The other half does not result from pelletierine 12 but must be something similar in structure since it does contain the piperideine unit (8) resulting from lysine. It was of interest then to determine the exact source of the three-carbon propionate unit in pelletierine (12). 

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