Hexanoic anhydride

Li etal. (2000b) investigated the reaction of wood with acetic, propionic, butyric, isobutyric or hexanoic anhydrides. The pre-extracted samples were vacuum impregnated... 

The combined catalyst system of TiCl(OTf)3 and TfOH allows the acylation of benzene and toluene with hexanoic anhydride (66% and 61% yields, respectively).56... 

The best results are obtained with a fractionating column surrounded by an electrically heated jacket but this is not essential for hexanoic anhydride. For the preparation of propanoic or butanoic anhydride, a highly efficient fractionating column must be used in order to obtain satisfactory results. 

In this resolution involving transesterification, the enzyme is catalysing the acetylation by vinyl acetate of the hydroxyl group of 42 with S configuration. This use of vinyl acetate is now fairly common in enzymatic resolution (see Chadha and Manohar12) hexanoic anhydride is also sometimes used in this context. 

Crystalline BSA, dioxane, hexanoic anhydride, diethyleneglycol and glycerol were obtained from Sigma and used without any purification. 

Optimized reaction conditions previously described5 were used in this study. Hexanoic anhydride was used to graft a six-carbon chain length onto the lysine by an acylation reaction. The use of three equivalents of hexanoic anhydride per lysine residue lead to 95% of acylation of these residues. The number of ANS... 

This is an unsymmetrical anhydride. The I.U.P.A.C. names of the two parent carboxylic acids are ethanoic acid (two-carbon) and hexanoic acid (six-carbon). To name an unsymmetrical anhydride, the term anhydride is preceded by the names of the two parent acids. The I.U.P.A.C. name of this compound is ethanoic hexanoic anhydride. The common names of the two parent carboxylic acids are acetic acid and caproic acid. Thus, the common name of this compound is acetic caproic anhydride. 

Titanium(IV) monochlorotriflate [TiCl(OTf)3] (1% mol), in combination with triflic acid [TfOH] (10% mol), is highly efficient in the acylation of anisole with hexanoic anhydride at room temperature in acetonitrile or... 

Other carboxylic acids give mixed anhydrides in this reaction,180-182 but these readily disproportionate to the pair of symmetrical anhydrides. This provides a method of obtaining good yields of acid anhydrides that are difficultly accessible by other routes. In Org. Syn. Williams and Krynitzky183 describe the preparation of hexanoic anhydride from the acid and ketene. 

Fig. 2 Relationship Between Undissolved Fiber Solids and Reaction Time of Alkali-extracted, Steam Exploded Fibers During Heterogeneous Esterification (with Hexanoic Anhydride) in DMAc.

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