From acetic add

Acetic add, butyric acid, formic add, propionic acid from acetic add, butyric acid, formic add, propionic acid, other oxygenated aliphatic compounds Silicalite-1 [193]... 

Kulprathipanja, S. and Spehlmann, B.C. (2001) Direct removal of trace ionic iodide from acetic add. Proceedings of the 13th International Zeolite Conference, Montpellier, France, 8-13 )uly. 

Although a small sample of 2,4,6-trimethylpyrylium perchlorate may with care be recrystallized from acetic add to give white crystals, m.p. 245-247° dec., it is recommended that this not be done with larger quantities. The 2,4,6-trimethylpyrylium perchlorate is of satisfactory purity for use in the 4,6,8-trimethyl-azulene preparation without further purification. 

Allyl silanes react with a wide variety of electrophiles, rather like the ones that react with silyl enol ethers, provided they are activated, usually by a Lewis acid. Titanium tetrachloride is widely used but other successful Lewis acids include boron trifluoride, aluminium chloride, and trim ethyls ilyl tri-flate. Electrophiles include the humble proton generated from acetic add. The regiocontrol is complete. No reaction is observed at the other end of the allylic system. All our examples are on the allyl silane we prepared earlier in the chapter. 

Domino reactions are not a new invention - indeed, Nature has been using this approach for billions of years However, in almost of Nature s processes different enzymes are used to catalyze the different steps, one of the most prominent examples being the synthesis of fatty acids using a multi-enzyme complex starting from acetic add derivatives. 

Figure 17.14. Some unusual reactor configurations, (a) Flame reactor for making ethylene and acetylene from liquid hydrocarbons [Patton et al.. Pet Refin 37(11) 180, (195S)]. (b) Shallow bed reactor for oxidation of ammonia, using Pt-Rh gauze [Gillespie and Kenson, Chemtech, 625 [Oct. 1971)]. (c) Schoenherr furnace for fixation of atmospheric nitrogen, (d) Production of acetic add anhydride from acetic add and gaseous ketene in a mixing pump, (e) Phillips reactor for low pressure polymerization of ethylene (closed loop tubular reactor), (f) Polymerization of ethylene at high pressure.

Since a. stronger acid donates its proton to the anioa a weaker acid in an acid-base reaction, a rank-ordered list tells which bases are needed to deproto-nate which acids. For example, since acetic add (pAg = 4.75) is a stronger add than ethanol ipKg = 16), we know that the anion of ethanol (ethoxide ion, CHsCH O") will remove a proton from acetic add. Similarly, amide ion CNH.2), the anion of ammonia (pK = 35), will remove a proton from ethanol (piXa = 16). 

Purification of Acetic Ester The acetic ester prepared according to Reaction 6, even after it has been freed from acetic add and alcohol by shaking with sodium carbonate and calcium chloride respectively, dried over calcium chloride, and finally rectified, is not suitable for this preparation, since it reacts too violently with sodium. But if it is allowed to stand, after distilling, for some hours, over night at least, in a well-closed flask, over about its volume of granulated caldum chloride, and is then filtered, it may be used for the successful preparation of acetacetic ester. 

Example Butyric Add from Acetic Add (a) Preparation of Malonic Ester... 

Hexagonal leaflets from alcohol, prisms from acetic add, mp 184-186 . (a]/ 433.7° (e = 1.5 in abs ethanol) [cf] +23.3 (Wieland) [ojjy +32-1 (Fischer). Freely sol in hot ale. More sol in ether than cholic or desoxycholic acid. Sol in about 10 times its weight of ethyl acetate. Slightly sol in glacial acetic acid (about 0.2 g in 3 ml). More sol in benzene than desoxycholic acid. Insol in petr elber, gasoline, ligroin. water. 

Estimated from acetic add and phosgene production statistics. 

Typical rate enhancements and favourable equilibria of intramolecular reactions are illustrated by some reactions of succinic acid and its derivatives [IS]. The equilibrium constant for succinic anhydride formation from succinic add (Eqn. 31) is 3 X 10 moles/1 more favourable than that for acetic anhydride formation from acetic add (Eqn. 32), an analogous intermolecular reaction. A similar situation exists... 

Sodium acetate (anhydrous) [127-09-3] M 82.0, m 324 , d 4 1.53. Crystallise it from acetic add and keep it under vacuum for 10 hours at 120°. Alternatively, it crystallises from aqueous EtOH as the trihydrate. This material can be converted to anhydrous salt by heating slowly in a porcelain, nickel or iron dish, so that the salt liquefies. Steam is evolved and the mass again solidifies. Heating is now increased so that the salt melts again. (NB if it is heated too strongly, the salt can char, avoid this.) After several minutes, the salt is allowed to solidify and is cooled to a convenient temperature (in a desiccator) before being powdered and bottled. The water content shonld now be less than 0.02%. [Beilstein 2II 113, 2 III 184, 2IV 109 ]... 

The first step in fatty acid biosynthesis involves the formation of a thiol ester, acetyl coenzyme A (acetyl CoA), from acetic add (present in the primary metabolic pool) and the thiol group (mercapto, or —SH group) of the coenzyme (HSCoA). A thiol ester is an ester in which the single-bonded oxygen (from the alcohol component) is replaced by a sulfur atom. 

Purification and Characterization. Determine the melting point of the oxime. It is of sufficient purity to proceed with the next step of the sequence if its mp is 187 °C or greater. If necessary, recrystaUize the material from acetic add or hot acetone. 

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