Hydrolysis with potassium hydroxide

Carbohydrate lactones have been used as the carbonyl reagent in the Reformatsky reaction. Thus, 2,3 5,6-di-O-cyclohexylidene-D-mannono-1,4-lactone [44, obtained by oxidation of the mannofuranose derivative (49)] reacted with ethyl bromoacetate and zinc to give the protected 2-deoxy-3-octulosonic acid ethyl ester (45a) in 69% yield (50). Ketonic hydrolysis with potassium hydroxide in aqueous methanol, followed by acidification and heating, afforded the 1-deoxyheptulose derivative 45b. Similarly, starting from compound 44, the 1-C-substituted allyl and propar-gyl lactols were prepared on reaction with allyl or propaigyl bromides in the presence of zinc (51). 

Ethyl hydrogen malonate may be prepared from diethyl malonate by controlled hydrolysis with potassium hydroxide (see also Expt 5.147, Note (1)). 

Acylation of 2-methylpyrazine with the Vilsmeier reagent gives 3-dimethylamino-2-(2-pyrazyl)acrolein (31) and this on hydrolysis with potassium hydroxide is converted into the malondialdehyde... 

A stereospecific synthesis of (S)-(—)-cathinone that utilizes the Friedel-Crafts reaction has been described (3/7). Reaction of the acid chloride obtained from /V-(methoxycarbonyl)-L-alanine (10) in benzene by A1C13 catalysis provided the N-protected a-amino ketone 11 with retention of chiralty 11 was deprotected by hydrolysis with potassium hydroxide. A more recently published method (408)... 

Hydrolysis of xenon hexafluoride or tetrafluoride with a sodium hydroxide solution results in the precipitation of a stable xenon (VIII) salt, sodium perxenate, Na4XeOe, which on heating does not decompose until around 300°. Similar hydrolysis with potassium hydroxide can yield a yellow precipitate which is a mixed potassium perxenate-xenon trioxide salt, and is explosive even when damp. With more concentrated base, the much more stable hydrated perxenate may be isolated. 

Carboxyphenyl carboxymethyl tellurium refluxed in acetic anhydride yielded 3-acet-oxybenzotellurophene, which, upon hydrolysis with potassium hydroxide, gave 3-hydr-oxybenzotellurophene. According to spectroscopic data, 3-hydroxybenzotellurophene exists in the form of 3-oxo-2,3-dihydrobenzotellurophene. This method of preparing 3-oxo-2,3-dihydrobenzotellurophene is laborious and gives low yields. ... 

S-2-Naphthyl dimethylthiocarbamate, hydrolysis with potassium hydroxide to 2-naphthalenethiol,... 

Four kinds of cycloalky[c]thiophaies were prepared by Riihe et al [16]. Diethyl thioglycolate was reacted with cylohexadione, followed by hydrolysis with potassium hydroxide. The resulting 2,5-dicarboxycyclo-hexa[c]thiophene was decarboxylated by refluxing in quinoline in the presence of a copper catalyst to produce cyclohexa[c]thiophene. They produced other cycloalk-yl(c)thiophenes via more complicated procedures. 

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