Methyl 3-nitroacrylate

Results of recent study, however, have been interpreted in terms of a homo-lytic process. Schechter and Conrad [49] have observed that the production of methyl-3-nitroacrylate and methyl-2-hydroxy-3-nitropropionate in the reaction between N204 and methyl acrylate could not be explained on the basis of heterolytic addition, but was to be expected if a homolytic process were occurring. Brown [80] has shown that olefin nitration under circumstances in which the nitronium ion (N02+) is the reactant has characteristics entirely different from those of the N204-olefin reaction. Brand and I. D. R. Stevens [81] also believed the reaction of addition of nitrogen dioxide to olefins to involve radicals. According to these authors the following experimental facts provide evidence for this ... 

The Diels-Alder reaction between 3-(2-nitroethenyl)indole (229) and methyl 3-nitroacrylate (230) in the presence of aluminum chloride in boiling toluene was shown to lead to the formation of both the nitro carbazole species 233 and 235, in very low yield (8%, 1 10), and the corresponding compounds without the nitro group, 234 and 236 (25%, 10 1) [90]. The reaction was presumed to proceed via the cycloaddition adducts 231 and 232 (34%, 3 2), followed by dehydrogenation and denitration (Scheme 51). 

Anisimova NA, Berkova GA et al (2006) Reaction of methyl 3-nitroacrylate with 3-(2-nitroethenyl)indole. Russ J Org Chem 42 1246-1247... 

Although commercially available, 1-trimethylsilyloxy-1,3-butadiene (1) can be easily prepared by silylation of crotonaldehyde. It has often been used as a reactive diene in Diels-Alder reactions. For example, reaction with dimethyl acetylenedicarboxylate (2) affords the cyclohexadiene diester (3) in 68% yield. This initial Diels-Alder adduct can be converted into two different aromatic products by the proper choice of conditions namely, thermal elimination affords the phthalate (4), while oxidation produces the phenol (5), hoth in good yield (eq 1). Reaction with methyl 3-nitroacrylate (6) followed hy hydrolysis of the initial adduct (7) and elimination of the -nitro group leads to the cyclohexadienol (8) (eq 2). Many other Diels-Alder reactions of this type have been carried out using (1), as shown in Table 1. In general, the endo adduct is favored, especially at lower temperatures. 

In their pioneering work. Just and co-workers have described many interesting transformations of the Diels-Alder adducts of furan to methyl nitroacrylate (77 + 77 ) and to dimethyl acetylenedicarboxylate (53). The mixture of racemic adducts 77 + 77 was hydroxylated into the exo-cis-diols 125 + 125 , separable by crystallization. Treatment of the isopropylidene acetal obtained from 125 with diazabicyclo[5.4.0]undec-5-ene (DBU) gave a high yield of alkene 126. Ozonolysis followed by a reductive work-up with dimethylsulfide, then with NaBH4, gave a mixture of epimeric triols 127. Cleavage with sodium periodate afforded 2,5-anhydro-3,4-0-isopropylidene-DL-allose (128) in 15 % yield, based on methyl 2-nitroacrylate used. TTie same allose derivative was obtained from adduct 53. ... 

The tryptophan side-chain can also be introduced using methyl 2-ethoxy-1-nitroacrylate as an clcctrophile[l 7b]. Vinylation occurs at room temperature by addition elimination. Reduction by SnCl2 followed by acylation generates A -acyl-o(, 3-dehydrotryptophans. 

Recently, enhanced endo selectivity has been reported in the Diels-Alder reaction of fE -l-acetoxybuta-l,3-dienes with methyl fi-nitroacrylate The selectivity is compared with that of the reaction using l-methoxybuta-l,3-dienes and 1-trimethylsilyloxybuta-1,3-di-enes The degree of electron richness of a diene is an important consideration in endo eKO selectivity issues In particular, electron-rich dienes favor the formation of fixc-nitrocycload-ducts fEq 8 9 ... 

Esters and ketones bearing P-nitro groups can be prepared in many ways. For example, the Diels-Alder reaction of methyl P-nitroacrylate is one typical case. Various cyclic dienes are prepared by this route, and the reactions of Eq. 7.121167 andEq. 7.122168 are exemplified. 

Functionalized nitroalkenes are important dienophiles in the Diels-Alder reaction. For example, ( )-methyl P-nitroacrylate is an important reagent in organic synthesis. The nitro group can be readily eliminated the Diels-Alder reaction of P-nitroacrylate is equivalent to that of ethyl propiolate with an inverse regiochemistry (Eq. 8.4).11... 

Racemic analogs of showdomycin have been synthesized from adducts (352 and 353) of methyl 2-nitroacrylate with furan. Synthesis of DL-2-ept-showdomycin involved treatment of the adducts with m-chloroperoxybenzoic acid, followed by nitrous acid elimination, to give the alkenic epoxide 379. Opening of the oxirane ring, and a sub-... 

Chiara and coworkers30 could show by IR spectroscopy that the form 18Z of methyl 3-amino-2-nitroacrylates with a hydrogen bond to the nitro group exists in two conformations (B and B") with different orientations of the ester group. NMR spectra showed only two forms in ratios near 1 1, fairly insensitive to the solvent. Evidently the B -B" exchange is rapid on the NMR time-scale in the explored temperature region. The barriers to thermal Z-E rotation in these compounds fall in the range 20-27 kcal mol 151. 

DL-2 -Deoxyshowdomycin (58) was totally synthesized starting from the cycloaddition product 130 of furan (102) and methyl 2-nitroacrylate as shown in Scheme 24 (77CJC2993). 

In continuing their studies on the synthesis of racemic C-nucleosides, Just and co-workers have reported the synthesis of DL-2 -deoxyshowdomycin (81) from furan and methyl P-nitroacrylate (Scheme 17), of a nitrogen analogue (82) of... 

Phenyl vinyl sulphoxide (129) has been shown to be a highly convenient acetylene Diels-Alder synthon, while methyl frans-jS-nitroacrylate (130) complements the use of acetylenic dienophiles, affording adducts with the opposite regiochemical substitution pattern, following nitrous acid elimination. ... 

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