Functional group formation

Asgari, R, and Argyropoulos, D. S., Fundamentals of oxygen delignification. Part II. Kinetics of functional group formation/elimination in residual kraft lignin, Can. J. Chem. 76, 1606-1615 (1998). 

Figure 6. Effect of processing at 200° C on functional group formation in HIPS...

Alkylation is the addition of the alkyl group to an active functional group, formation of methyl esters being the most useful derivatisation reaction. A number of reagents are available but boron trifluoride in methanol is most commonly used. 

Multicatalytic domino processes are synthetic strategies in which two or more catalytic domino reactions are sequentially used in the synthesis of a compound Hbrary [8-10]. The product obtained from the first domino reaction is the substrate for subsequent cascades, which yield products with either a different scaffold or modified functional group formation. 

Gugumus F (1996) Thermooxidative degradation of polyolefins in the soUd state Part 1. Experimental kinetics of functional group formation. Polymer Degradation and Stability 52 131-144... 

ABS is considerably more thermally sensitive than other styrene copolymers because of its butadiene phase with unsaturated monomer units. Damage occurs mainly in the butadiene phase, while the styrene phase remains comparatively stable. Double bonds are cleaved and subsequently crosslinking or functional group formation is detected. 

B. Influence of Laser Treatment on the Ablation, Morphology, and Functional Group Formation on PO Surfaces... 

The success of the last reaction depends upon the inertness of the ester carbonyl groups towards the organocadmium compound with its aid and the use of various ester acid chlorides, a carbon chain can be built up to any reasonable length whilst retaining a reactive functional group (the ester group) at one end of the chain. Experimental details are given for l-chloro-2-hexanone and propiophenone. The complete reaction (formation of ketones or keto-esters) can be carried out in one flask without isolation of intermediates, so that the preparation is really equivalent to one step. 

Regioselectivity of C—C double bond formation can also be achieved in the reductiv or oxidative elimination of two functional groups from adjacent carbon atoms. Well estab llshed methods in synthesis include the reductive cleavage of cyclic thionocarbonates derivec from glycols (E.J. Corey, 1968 C W. Hartmann, 1972), the reduction of epoxides with Zn/Nal or of dihalides with metals, organometallic compounds, or Nal/acetone (seep.lS6f), and the oxidative decarboxylation of 1,2-dicarboxylic acids (C.A. Grob, 1958 S. Masamune, 1966 R.A. Sheldon, 1972) or their r-butyl peresters (E.N. Cain, 1969). 

Since (A) does not contain any other functional group in addition to the formyl group, one may predict that suitable reaction conditions could be found for all conversions into (A). Many other alternative target molecules can, of course, be formulated. The reduction of (H), for example, may require introduction of a protecting group, e.g. acetal formation. The industrial synthesis of (A) is based upon the oxidation of (E) since 3-methylbutanol (isoamyl alcohol) is a cheap distillation product from alcoholic fermentation ( fusel oils ). The second step of our simple antithetic analysis — systematic disconnection — will now be exemplified with all target molecules of the scheme above. For the sake of brevity we shall omit the syn-thons and indicate only the reagents and reaction conditions. 

The fundamental problem of oligodeoxyribonucleotide synthesis is the efficient formation of the intemucleotidic phosphodiester bond specifically between C-3 and C-5 positions of two adjacent nucleosides. Any functional group (NH of nucleic base the other OH of deoxy-... 

This method is widely used for the resolution of chiral amines and carboxylic acids Analogous methods based on the formation and separation of diastereomers have been developed for other functional groups the precise approach depends on the kind of chem ical reactivity associated with the functional groups present m the molecule... 

Polyesters are a second class of condensation polymers and the principles behind their synthesis parallel those of polyamides Ester formation between the functional groups of a dicarboxylic acid and a diol... 

The carbon-carbon bond forming potential inherent m the Claisen and Dieckmann reac tions has been extensively exploited m organic synthesis Subsequent transformations of the p keto ester products permit the synthesis of other functional groups One of these transformations converts p keto esters to ketones it is based on the fact that p keto acids (not esters ) undergo decarboxylation readily (Section 19 17) Indeed p keto acids and their corresponding carboxylate anions as well lose carbon dioxide so easily that they tend to decarboxylate under the conditions of their formation... 

Aldoses incorporate two functional groups C=0 and OH which are capable of react mg with each other We saw m Section 17 8 that nucleophilic addition of an alcohol function to a carbonyl group gives a hemiacetal When the hydroxyl and carbonyl groups are part of the same molecule a cyclic hemiacetal results as illustrated m Figure 25 3 Cyclic hemiacetal formation is most common when the ring that results is five or SIX membered Five membered cyclic hemiacetals of carbohydrates are called furanose forms SIX membered ones are called pyranose forms The nng carbon that is derived... 

Section 27 5 Ammo acids undergo reactions characteristic of the ammo group (e g amide formation) and the carboxyl group (e g esterification) Ammo acid side chains undergo reactions characteristic of the functional groups they contain... 

Allylic rearrangement (Section 10 2) Functional group trans formation in which double bond migration has converted one allylic structural unit to another as in... 

Fingerprint region (Section 13 20) The region 1400-625 cm of an infrared spectrum This region is less character istic of functional groups than others but varies so much from one molecule to another that it can be used to deter mine whether two substances are identical or not Fischer esterification (Sections 15 8 and 19 14) Acid cat alyzed ester formation between an alcohol and a carboxylic acid... 

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