Olefinic adds nitro compounds

Michael condensations are catalyzed by alkaU alkoxides, tertiary amines, and quaternary bases and salts. Active methylene compounds and aUphatic nitro compounds add to form P-substituted propionates. These addition reactions are frequendy reversible at high temperatures. Exceptions are the tertiary nitro adducts which are converted to olefins at elevated temperatures (24). 

In a variation of the Michael condensation, nitroparaffins having active methylene groups add to reactive olefinic compounds including ot,/3-unsaturated esters (method 301), a.,y6-unsaturated cyanides (method 388), and a-nitro olefins. Interaction of primary or secondary aliphatic nitro compounds with the unsaturated nitro compounds in the presence of sodium ethoxide in alcohol yields 1,3-dinitroparaffins. The reaction is general, but the yields vary, depending on the degree of polymerization that the nitro olefin undergoes and the amount of addition of alcohol to it as well as on the reactivity of the product toward further condensation. 

An interesting topological effect is the increased terminal chlorination of fatty acids when they are adsorbed and aligned on alumina Silicon disulfide and particularly boron sulfide have been used with advantage instead of phosphorus pentasulfide to replace carbonyl oxygen by sulfur The addition of sulfur monochloride to olefins followed by reduction of the adduct with sodium sulfide provides a convenient inexpensive route to a large number of episulfides A direct conversion of ar. nitro compounds to isothiocyanates has been reported Sec. phosphines add easily to olefins under UV-irradiation Advances in peptide synthesis include the use of acyloxyphospho-nium salts prepared with hexamethylphosphoramide a simple synthesis with triphenyl phosphite , and the use 4-picolyl esters at the... 

Asymmetric Michael addition of optically active perhydro-l,4-oxazepin-5,7-diones, and of thioglycollic acid in the presence of a cinchona alkaloid as catalyst, to a-nitro-olefins yields y-nitrocarboxylic acids and 2-nitrothio ethers, respectively, with reasonable enantiomeric excess. Allylsilanes add to a-nitro-olefins in the presence of aluminium chloride to give unsaturated nitronic acids, which are further transformed in a Nef-type reaction to give y,5-enones (Scheme 36).Nitro-compounds are also converted into the corresponding carbonyl compounds upon treatment with base and MoOs pyHMPA, a new modified Nef reaction. 

Dipolar addition to unsaturated compounds affords routes to unique and interesting structures. The 1,3-dipolar cycloaddition of the 0-methyl ether of dinitromethane to methyl acylate produced N-methoxy-3-nitro-5-carbomethoxy-isoxazolidine in 65% yield. Similar results were obtained with other olefins. Acetonitrile N-oxide adds to enynes to form isoxazolines and isoxazoles. ... 

A clever route to thienium salts from a nitro olefin like 19 has recently been described.46 Treatment of 19 with aluminum chloride provides a thienium intermediate that adds to various 1,3-dienes. The product of [4 + 2] cycloaddition was not detected, rather a ring-opened compound was produced (Scheme 5-XVII). Some additional examples of this reaction are... 

Dinitrogen tetroxide adds to olefinic double bonds with formation of dinitro compounds and nitro nitrites the latter are unstable and are readily oxidized to nitro nitrates or hydrolysed to nitro alcohols in the presence... 

Vinyl chloride,29 vinyl acetate,30 oc-nitro olefins,31 and azlactones32 also add alkanethiols. The reaction of azlactones is accompanied by ring fission to yield V-acyl / -alkylthio oc-amino thioesters, this being a good preparative route to such compounds ... 

Unlike most free radicals, 02 has little tendency to add to carbon-carbon double bonds it has been shown to be inert with most simple olefins as well as many aromatic hydrocarbons. It reacts with electron-poor aromatic compounds such as quinones and nitro derivatives to produce radical anions (Wilshire and Sawyer,... 

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