Mozingo reaction

A popular two-step protocol for the deoxygenation of carbonyl compounds is the Mozingo reaction in which the aldehyde or ketone is transformed to a dithioacetal in the presence of a Lewis acid and then reductive desulphurization is carried out with Raney The reaction is mild, efficient and particularly convenient for small-scale... 

A modification of the K-R reaction was introduced by Mozingo. This method involved reacting an o-hydroxyacetophenone with an ester in the presence of metallic sodium to form a 1,3-diketone. Treatment of the diketone with an acid then delivered the chromone via an intramolecular cyclization reaction. This method was applied to the preparation of 2-ethylchromone (21). 0-hydroxyarylketone 22 was allowed to react with ethyl propionate (23) in the presence of sodium metal.The resulting sodium enolate was then quenched with acetic acid to deliver the 1,3-diketone 24. Upon heating 24 in glacial acetic acid and hydrochloric acid, 2-ethylchromone (21) was delivered in 70-75% overall yield. 

M. B. Smith, J. March in March s Advanced Organic Chemistry, 5th ed., John Wiley and Sons, Inc., New York, 2001, p. 532 T. Laue, A. Plagens, Named Organic Reactions, John Wiley and Sons, Inc., New York, 1998, pp. 232-233 E. Mosettig, R. Mozingo, Organic Reactions 4, 7... 

Bernstein and Dorfman (18) have prepared a modified catalyst by allowing the reaction mixture to stand at room temperature overnight after the addition of the alloy. Bougault, Cattelain, and Chabrier (19) and Mozingo (20) have prepared similarly modified catalysts. 

Mozingo (20) has shown with a wide variety of compounds that Raney nickel catalyst in the presence of a solvent and with only its adsorbed hydrogen can cleave either reduced or oxidized sulfur from the remainder of the molecule at a moderate temperature. Two courses for the reaction can be postulated ... 

Similar postulates can be written for the reactions of disulfides, sulfoxides, and sulfones. Only reaction B was observed by Mozingo, who used sufficient catalyst to contain a large excess of adsorbed hydrogen. 

Mozingo, Folkers, and co-workers (143) used the desulfuration reaction in the determination of the structures of biotin and its derivatives. 

Mosettig and Mozingo in Organic Reactions, Vol. 4, John Wiley Sons, New York, 1948, p. 362. 

An aldehyde (RCHO) or ketone (RCOR) can therefore be reduced to an alkane via a hydrazone. This transformation can also be achieved using the Oxidation levels can be used to Mozingo reduction (see Section 8.3.6) or the Clemmensen reduction (shown assess if a reaction involves... 

If the alkyne contains an alcohol group, this may attack the ketene intermediate leading to a lactone after oxidative removal of the chromium (Scheme 8.28). This reaction has been used in syntheses of blast-mycinone 8.106 and antimycinone 8.107, starting from a protected lactaldehyde 8.102, and employing the Mozingo method at the end to remove the undesired keto group from the ketene cyclization product 8.105 (Scheme 8.29) ... 

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