Orgo 11.1-11.5

Oxidation of alcohols leads to __, __, and _. These functional groups, in turn, undergo a wide variety of additional reactions. For these reasons, __ are some of the most common organic reactions.

In inorganic chemistry, we think of oxidation as __ and reduction as __. Most organic compounds are uncharged, and gain or loss of electrons is not obvious. Organic chemists tend to think of oxidation as the result of __ and reduction as the result of __.

Explain: 
oxidation
reduction
neither

How can we tell an oxidation or reduction of an alcohol has taken place? 

Oxidation usually does what?

A __ is more oxidized than an __ because the __ has one bond to oxygen, while the __ has no bonds to oxygen.

Oxidation of a primary alcohol gives an __ with a carbonyl carbon having __ bonds to oxygen. Oxidation of the __to an acid adds __ to oxygen, for a total of __. Further oxidation would require what to give four bonds to oxygen, the oxidation state of __.

Oxidation of a primary or secondary alcohol forms __ by the removal of two hydrogen atoms: one from __ and one from __.

Why can't tertiary alcohols do this?

Primary and secondary alcohols are easily oxidized by a variety of reagents, including __, __, __, and even __. The choice of reagent depends on __. Many of the traditional oxidants are based on __ because they are highly toxic, and they are difficult to dispose of properly.

All of the oxidizing agents have what and do what?

What are the steps of oxidation of a secondary alcohol.

Secondary alcohols are easily oxidized to give excellent yields of __. The __ is often used for lab oxidations of secondary alcohols. The __ is prepared by dissolving __ in a mixture of __ and water. The active species in the mix is probably __ or the __. Adding __ to __ achieves the same result.

The mechanism of chromic acid oxidation
1: __
2: __ gives the __.

In the elimination, the carbinol carbon does what but loses what and gains what?

The __ formed reacts further to give the stable reduced form, __. Both __ and __ are orange, but __ is a deep blue.

Oxidation of primary alcohols
Oxidation of a primary alcohol initially forms an __. Unlike a __, however, an __ is easily oxidized further to give a __. 

Obtaining the __ is often difficult, since most oxidizing agents strong enough to oxidize primary alcohols also oxidize __. __ generally oxidizes a primary alcohol all the way to a __.

A better reagent for the limited oxidation of primary alcohols to aldehydes is __, a complex of chromium trioxide with pyridine and HCl. __ oxidizes most primary alcohols to aldehydes in excellent yields. Unlike most other oxidants, __ is soluble in nonpolar solvents such as __, which is an excellent solvent for most organic compounds. __ can also serve as a mild reagent for oxidizing secondary alcohols to ketones.

Oxidation of tertiary alcohols is not important because what?

The __ for primary and secondary alcohols exploits the resistance of __ to oxidation. When a __ or __ is added to the __, the orange color changes to green or blue. When a nonoxidizable substance is added to the reagent, no immediate color change occurs.

The __ is a complex o chromium trioxide and pyridine, the original version of PCC. The __ is a milder form of chromic acid: a solution of diluted chromic acid in acetone.

In many cases, simple oxidants such as household bleach can accomplish the same oxidations as chromic acid without using __ and without generating hazardous wastes.

Oxidations using __ involve mildly acidic or basic conditions that may be better than chromic acid for acid-sensitive compounds. Two other strong oxidants are __ and __. Both are less expensive and produce less ehazardous. They both oxidize __ to __ and __ to __.

The __ uses dimethyl sulfoxide (DMSO) as the oxidizing agent to convert acohol to ketones and aldehydes. DMSO and oxalyl chlroide are added to the alcohol at low temp, followed by a hindered base such as triethylamine. The reactive species, formed in the solution, is thought to act as the __ in the __. __ are oxidized to __ and __ are oxidized only as far as the __. The byproducts of this reaction are all __ and are easily separated from the organic products.

Like the Swern oxidation, the __ reagent oxidizes primary alcohols to __ and secondary alcohols to __ without using chromium or other heavy-metal compounds. THe reaction with __ takes place under mild conditions and gives excellent yields. The __ reagent, which owes its oxidizing ability to a __, is a commercially available solid that is easily stored.

Although it is the least toxic alcohol, __ is still poisonous. To detoxify it, the liver produces an enzyme called __, which catalyzes an oxidation: __.

The oxidizing agent is __, which exists in two forms: the oxidized __ and the reduced __

A subsequent oxidation, catalyzed by __, converts acetaldehyde to acetic acid, a normal metabolite. These oxidations take place with most small __. Unfortunately, the oxidation products of some other alcohols are more toxic than __. Methanol is oxidized first to __ and then to __. Both of these compounds are more toxic than methanol itself.

Alcohols react as both __ and __. An alcohol is easily converted to a __ by forming its __. THe __ can attack a weaker __, such as an __.

The O-H bond is broken when alcohols react as __, both when an __ reacts as a weak __, or when an alcohol is converted to its __ that then reacts as a __. In contrast, when an alcohol reacts as an __, the C-O bond is broken.

Why is an alcohol a weak electrophile? 

The hydroxyl group becomes a good leaving group when __.

The disadvantage of using a protonated alcohol is that a __ is required to protonate the alcohol. Although __ are stable in acid, few other good nucleophiles are stable in strongly acidic solutions.

Most strong nucleophiles are also __ and will __. Once protonated, the reagent is no longer __. 

How can we convert an alcohol to an electrophile that is compatible with basic nucleophiles?

A __ is the product of condensation of an alcohol with p-toluenesulfonic acid (TsOH). The __ is an excellent leaving group, and __ undergo __ and __ much like alkyl halides. In many cases, a __ is more reactive than the equivalent alkyl halide.

__ are made from alcohols using __ in pyridine. This reaction gives much higher yields than the reaction with TsOH itself. The mechanism of __ formations shows that the C-O bond of the alcohol remains intact throughout the reaction, and the alcohol retains its __. __ serves as an organic base to remove the HCl formed in the reaction, preventing it from protonating the alcohol and causing side reactions.

The tosylate ion is a particularly __, with its negative charge delocalized over __.
Like halides, the __ is displaced by a wide variety of nucleophiles. The __ is more commonly used than the __.