Alcohol reaction summary

Mills and coworkers (37) performed a series of MPV reductions of cyclic ketones to the corresponding epimeric mixtures of alcohols using aluminum isopropoxide as the catalyst in isopropyl alcohol. A summary of their results is given in Table 2. They conclude that the predominant influence in these reductions pertinent to the cis/trans ratio of the resulting epimeric alcohol mixtures is the degree of steric hindrance of the carbonyl moiety. They also separately investigated (38) a series of MPV reductions of aldehydes and unstable ketones where slow, drop-wise addition of the carbonyl substrate to the reactions inproved the yields. 

Summary of Reactions Discussed in Earlier Chapters That Yield Alcohols... 

Summary of Reactions of Alcohols Discussed in Earlier Chapters... 

In summary the Mitsunobu reaction can be described as a condensation of an alcohol 1 and a nucleophile—NuH—11, where the reagent triphenylphosphine is oxidized to triphenylphosphine oxide and the azodicarboxylate reagent 12 is reduced to a hydrazine derivative 13 ... 

Figure 11.6 Summary of importrant reactions of alcohols and ethers starting with ethanol.

In summary, the secondary and tertiary alcohols are more reactive and lead to more bond cleavage reactions, especially with Cu+. Coordination numbers >2 were not observed in this study. 

In summary, the structure of a reagent formed from the reaction of LAH with an alcohol cannot be assumed on the basis of the stoichiometry of the reagents, because of the possibility of disproportionation. With very highly hindered alcohols or phenols, tricoordinate species may be formed. 

This method was extensively reviewed in <84CHEC-I(4)545> and a brief summary is presented here interestingly, since the mid-1980s, this reaction has become less popular. A(-Aryl benzhydrazonyl chlorides react with thiobenzamides to form trisubstituted thiadiazolines which on treatment with alcohols furnish the 2-alkoxy derivative (Scheme 25). A-Arylbenzhydrazonyl chlorides also react with thioketenes to yield 5-methylene thiadiazolines (Equation (16)). Other examples involve the addition of the nitrileimine generated from A-trifluoroacetobenzhydrazonyl bromide to the 0=S of potassium isothiocyanate and methyl isocyanate <87JHC1391>. 

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