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In the indirect method, the alkene is converted to the sulfate ester, which is subsequently hydrolyzed.
The direct hydration using ethylene (ethylene hydration) or other alkenes from cracking of fractions of distilled crude oil.
Hydration is also used industrially to produce the diol ethylene glycol from ethylene oxide.
========,3,Biological routes.
Ethanol is obtained by fermentation using glucose produced from sugar from the hydrolysis of starch, in the presence of yeast and temperature of less than 37 °C to produce ethanol.
For instance, such a process might proceed by the conversion of sucrose by the enzyme invertase into glucose and fructose, then the conversion of glucose by the enzyme complex zymase into ethanol (and carbon dioxide).
Several of the benign bacteria in the intestine use fermentation as a form of anaerobic metabolism.
This metabolic reaction produces ethanol as a waste product, just like aerobic respiration produces carbon dioxide and water.
Thus, human bodies contain some quantity of alcohol endogenously produced by these bacteria.
In rare cases, this can be sufficient to cause "auto-brewery syndrome" in which intoxicating quantities of alcohol are produced.
========,4,Substitution.
Primary alkyl halides react with aqueous NaOH or KOH mainly to primary alcohols in nucleophilic aliphatic substitution.
(Secondary and especially tertiary alkyl halides will give the elimination (alkene) product instead).
Grignard reagents react with carbonyl groups to secondary and tertiary alcohols.
Related reactions are the Barbier reaction and the Nozaki-Hiyama reaction.
========,4,Reduction.
Aldehydes or ketones are reduced with sodium borohydride or lithium aluminium hydride (after an acidic workup).
Another reduction by aluminiumisopropylates is the Meerwein-Ponndorf-Verley reduction.
Noyori asymmetric hydrogenation is the asymmetric reduction of β-keto-esters.
========,4,Hydrolysis.
Alkenes engage in an acid catalysed hydration reaction using concentrated sulfuric acid as a catalyst that gives usually secondary or tertiary alcohols.
The hydroboration-oxidation and oxymercuration-reduction of alkenes are more reliable in organic synthesis.
Alkenes react with NBS and water in halohydrin formation reaction.
Amines can be converted to diazonium salts, which are then hydrolyzed.
The formation of a secondary alcohol via reduction and hydration is shown:
========,2,Reactions.
========,3,Deprotonation.
Alcohols behave as weak acids, undergoing deprotonation, but strong bases are required.
The deprotonation reaction to produce an alkoxide salt is performed with a strong base such as sodium hydride or sodium metal.
Water is similar in pK to many alcohols, so with sodium hydroxide an equilibrium exists, which usually lies to the left:
The acidity of alcohols is strongly affected by solvation.
In the gas phase, alcohols are more acidic than is water.
========,3,Nucleophilic substitution.
The OH group is not a good leaving group in nucleophilic substitution reactions, so neutral alcohols do not react in such reactions.
However, if the oxygen is first protonated to give R−OH, the leaving group (water) is much more stable, and the nucleophilic substitution can take place.
For instance, tertiary alcohols react with hydrochloric acid to produce tertiary alkyl halides, where the hydroxyl group is replaced by a chlorine atom by unimolecular nucleophilic substitution.
If primary or secondary alcohols are to be reacted with hydrochloric acid, an activator such as zinc chloride is needed.
In alternative fashion, the conversion may be performed directly using thionyl chloride.
Alcohols may, likewise, be converted to alkyl bromides using hydrobromic acid or phosphorus tribromide, for example:
In the Barton-McCombie deoxygenation an alcohol is deoxygenated to an alkane with tributyltin hydride or a trimethylborane-water complex in a radical substitution reaction.
========,3,Dehydration.
Alcohols are themselves nucleophilic, so R−OH can react with ROH to produce ethers and water in a dehydration reaction, although this reaction is rarely used except in the manufacture of diethyl ether.
More useful is the E1 elimination reaction of alcohols to produce alkenes.
The reaction, in general, obeys Zaitsev's Rule, which states that the most stable (usually the most substituted) alkene is formed.
Tertiary alcohols eliminate easily at just above room temperature, but primary alcohols require a higher temperature.
This is a diagram of acid catalysed dehydration of ethanol to produce ethene:
A more controlled elimination reaction is the Chugaev elimination with carbon disulfide and iodomethane.
========,3,Esterification.
To form an ester from an alcohol and a carboxylic acid the reaction, known as Fischer esterification, is usually performed at reflux with a catalyst of concentrated sulfuric acid:
In order to drive the equilibrium to the right and produce a good yield of ester, water is usually removed, either by an excess of HSO or by using a Dean-Stark apparatus.
Esters may also be prepared by reaction of the alcohol with an acid chloride in the presence of a base such as pyridine.
Other types of ester are prepared in a similar manner for example, tosyl (tosylate) esters are made by reaction of the alcohol with p-toluenesulfonyl chloride in pyridine.
========,3,Oxidation.
Primary alcohols (R-CH-OH) can be oxidized either to aldehydes (R-CHO) or to carboxylic acids (R-COH), while the oxidation of secondary alcohols (RRCH-OH) normally terminates at the ketone (RRC=O) stage.
Tertiary alcohols (RRRC-OH) are resistant to oxidation.
The direct oxidation of primary alcohols to carboxylic acids normally proceeds via the corresponding aldehyde, which is transformed via an "aldehyde hydrate" (R-CH(OH)) by reaction with water before it can be further oxidized to the carboxylic acid.
Reagents useful for the transformation of primary alcohols to aldehydes are normally also suitable for the oxidation of secondary alcohols to ketones.
These include Collins reagent and Dess-Martin periodinane.
The direct oxidation of primary alcohols to carboxylic acids can be carried out using potassium permanganate or the Jones reagent.
========,1,preface.
In Greek mythology the Erinyes (; sing.
Erinys ; , pl.
of , "Erinys"), also known as the Furies, were female chthonic deities of vengeance; they were sometimes referred to as "infernal goddesses" ().
A formulaic oath in the "Iliad" invokes them as "the Erinyes, that under earth take vengeance on men, whosoever hath sworn a false oath".
Walter Burkert suggests they are "an embodiment of the act of self-cursing contained in the oath".
They correspond to the Dirae in Roman mythology.
The Roman writer Maurus Servius Honoratus wrote that they are called "Eumenides" in hell, "Furiae" on earth, and "Dirae" in heaven.
According to Hesiod's "Theogony", when the Titan Cronus castrated his father, Uranus, and threw his genitalia into the sea, the Erinyes (along with the Giants and the Meliae) emerged from the drops of blood which fell on the earth (Gaia), while Aphrodite was born from the crests of sea foam.
According to variant accounts, they emerged from an even more primordial level—from Nyx ("Night"), or from a union between air and mother earth.
Their number is usually left indeterminate.
Virgil, probably working from an Alexandrian source, recognized three: Alecto or Alekto ("endless"), Megaera ("jealous rage"), and Tisiphone or Tilphousia ("vengeful destruction"), all of whom appear in the "Aeneid".
Dante Alighieri followed Virgil in depicting the same three-character triptych of Erinyes; in Canto IX of the "Inferno" they confront the poets at the gates of the city of Dis.
Whilst the Erinyes were usually described as three maiden goddesses, the Erinys Telphousia was usually a by-name for the wrathful goddess Demeter, who was worshipped under the title of Erinys in the Arkadian town of Thelpousa.
========,2,Etymology.
The word "Erinyes" is of uncertain etymology; connections with the verb ὀρίνειν "orinein", "to raise, stir, excite," and the noun ἔρις "eris", "strife" have been suggested; Beekes, pp.
458–459, has proposed a Pre-Greek origin.
The word "Erinys" in the singular and as a theonym is first attested in Mycenaean Greek, written in Linear B, in the following forms: , "e-ri-nu", and , "e-ri-nu-we".
These words are found on the KN Fp 1, KN V 52, and KN Fh 390 tablets.
========,2,Description.
The Erinyes live in Erebus and are more ancient deities than any of the Olympians.
Their task is to hear complaints brought by mortals against the insolence of the young to the aged, of children to parents, of hosts to guests, and of householders or city councils to suppliants - and to punish such crimes by hounding culprits relentlessly.
The Erinyes are crones and, depending upon authors, described as having snakes for hair, dog's heads, coal black bodies, bat's wings, and blood-shot eyes.
In their hands they carry brass-studded scourges, and their victims die in torment.
========,2,Erinyes in ancient Greek literature.
Tantalizing myth fragments dealing with the Erinyes are found among the earliest extant records of ancient Greek culture.
The Erinyes are featured prominently in the myth of Orestes, which recurs frequently throughout many works of ancient Greek literature.
========,3,Aeschylus.
Featured in ancient Greek literature, from poems to plays, the Erinyes form the Chorus and play a major role in the conclusion of Aeschylus's dramatic trilogy the "Oresteia".
In the first play, "Agamemnon", King Agamemnon returns home from the Trojan War, where he is slain by his wife, Clytemnestra, who wants vengeance for her daughter Iphigenia, who was sacrificed by Agamemnon in order to obtain favorable winds to sail to Troy.
In the second play, "The Libation Bearers", their son Orestes has reached manhood and has been commanded by Apollo’s oracle to avenge his father‘s murder at his mother’s hand.
Returning home and revealing himself to his sister Electra, Orestes pretends to be a messenger bringing the news of his own death to Clytemnestra.
He then slays his mother and her lover Aegisthus.
Although Orestes’ actions were what Apollo had commanded him to do, Orestes has still committed matricide, a grave sacrilege.
Because of this, he is pursued and tormented by the terrible Erinyes, who demand yet further blood vengeance.
In "The Eumenides", Orestes is told by Apollo at Delphi that he should go to Athens to seek the aid of the goddess Athena.
In Athens, Athena arranges for Orestes to be tried by a jury of Athenian citizens, with her presiding.
The Erinyes appear as Orestes’ accusers, while Apollo speaks in his defense.
The trial becomes a debate about the necessity of blood vengeance, the honor that is due to a mother compared to that due to a father, and the respect that must be paid to ancient deities such as the Erinyes compared to the newer generation of Apollo and Athena.
The jury vote is evenly split.
Athena participates in the vote and chooses for acquittal.