Polynitroaliphatic alcohols

The acetylenic bond of propargyl ethers can react with polynitroaliphatic alcohols, as in the case of ethoxyacetylene (125), which reacts with two equivalents of 2-fluoro-2,2-dinitroethanol (119) to give the orthoester (126). " ... 

Polynitroaliphatic alcohols are invaluable intermediates for the synthesis of energetic materials (see Section 1.11). The most important route to /i-nitroalcohols is via the Henry reaction where a mixture of the aldehyde and nitroalkane is treated with a catalytic amount of base, or the nitronate salt of the nitroalkane is used directly, in which case, on reaction completion, the reaction mixture is acidified with a weak acid. Reactions are reversible and in the presence of base the salt of the nitroalkane and the free aldehyde are reformed. This reverse reaction is known as demethylolation if formaldehyde is formed. 

The use of polynitroaliphatic alcohols as sources of the corresponding nitronate anions is common in addition reactions. However, polynitroaliphatic alcohols are useful in their own right. The hydroxy functionalities of 2,2-dinitroethanol, 2,2-dinitro-l,3-propanediol and... 

Polynitroaliphatic alcohols containing nitro groups on the carbon fi to the hydroxy functionality are less basic than their alkyl counterparts. This decreased basicity of the hydroxy group makes reactions such as esterification, acetal formation and alkylation much slower than usual, and in some cases, these reactions may not proceed without catalysts. To add to the problem, normal base catalysts cannot be used in conjunction with 2,2-dinitroalkanols and l,l,l-trinitro-2-alkanols because of their facile dissociation in alkaline solution. 

The weak nucleophilic nature of polynitroaliphatic alcohols means that reactions often need to be catalyzed by Brpnsted acids or Lewis acids. The following methods are commonly used for the esterification of polynitroaliphatic alcohols (1) heating a solution of the alcohol and acid in the presence of sulfuric acid with Dean-Stark removal of water ° (2) using the acid chloride or anhydride in the presence of aluminium chloride " (3) reacting the acid and alcohol... 

A huge number of ester and carbonate derivatives of polynitroaliphatic alcohol have been synthesized driven by the search for new explosives and energetic plasticizers and oxidizers for propellant and explosive formulations. Most of these are derived from 2-fluoro-2,2-dinitroethanol and 2,2,2-trinitroethanol ° and have excellent oxygen balances. Some examples are illustrated above (168-174) but more comprehensive lists can be found in numerous reviews. " " Direct esterification of polynitroaliphatic alcohols with nitric acid, mixed acid, or acetic anhydride-nitric acid has been used as a route to mixed polynitroaliphatic-nitrate ester explosives. ... 

Formals and acetals prepared from the reaction of polynitroaliphatic alcohols with formaldehyde and acetaldehyde have found use as explosive plastisizers for nitrocellulose and in plastic bonded explosives (PBXs). Formals of polynitroaliphatic alcohols are commonly prepared via reaction with trioxane or paraformaldehyde in the presence of sulfuric acid as a condensing agent. Bis(2,2-dinitropropyl)formal (175) is prepared from the reaction of trioxane with 2,2-dinitropropanol (25). The reaction of 2,2,2-trinitroethanol (159) and 2,2-dinitro-l,3-propanediol (19) with formaldehyde in the presence of sulfu-... 

Orthoesters of polynitroaliphatic alcohols have been synthesized in the presence of metal chloride Lewis acid catalysts. Tetrakis(2,2,2-trinitroethyl)orthocarbonate (180) and tris(2,2,2-trinitroethyl)orthoformate (181) are obtained from the reaction of 2,2,2-trinitroethanol (159) with carbon tetrachloride and chloroform, respectively, in the presence of anhydrous ferric chloride.333729 Analogous reactions with 2-fluoro-2,2-dinitroethanol have been reported.3 ... 

The weak nucleophilic nature of polynitroaliphatic alcohols is also reflected in their slow reactions with isocyanates to yield carbamates. These reactions often need the presence of Lewis acids like ferric acetylacetonate or boron trifluoride etherate. The reaction of bifunctional isocyanates with polynitroaliphatic diols has been used to synthesize energetic polymers.33°... 

Alkylations and other reactions using polynitroaliphatic alcohols as nucleophiles usually require Lewis acid catalysts. A comprehensive review of the chemistry of fluoronitro compounds. 

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