Spiro -2-ones

Figure Bl.2.11. Biologically active centre in myoglobin or one of the subunits of haemoglobin. The bound CO molecule as well as the proximal and distal histidines are shown m addition to the protohaeme unit. From Rousseau D L and Friedman J M 1988 Biological Applications of Raman Spectroscopy vol 3, ed T G Spiro (New York Wiley). Reprinted by pennission of John Wiley and Sons Inc.

Cyclohexanedione monoethylene acetal (l,4-dioxa-spiro[4.5]decan-8-one) [4746-97-8] M 156.2, m 70-73", 73.5-74.5". Recrystd from pet ether and sublimes slowly on attempted distillation. Also purified by dissolving in Et20 and adding pet ether (b 60-80°) until turbid and cool. [Gardner et al. J Am Chem Soc 22 1206 I957 Britten and Lockwood J Chem Soc Perkin Trans I 1824 1974.]... 

Carbocyclic spiro ring pairs generally are disconnected in two ways (1) one-bond... 

A-Homo-5a-cholestan-4-one (3b). A solution of sodium nitrite (2 g) in water (100 ml) is added over 1 hr to a stirred solution of 3-(5 -spiro-2, 2 -dimethyloxazolidinyl)-5a-cholestane (7 4.58 g) in aqueous 10% acetic acid (800 ml), maintained at 0-5° for 3 hr and the mixture is then allowed to stand overnight. The reaction mixture is neutralized with 10% sodium hydroxide solution and the resulting white suspension is extracted with ether. The ether extracts are washed with water, dried and concentrated to give a semisolid residue which is converted to the semicarbazone by warming in methanol solution (ca. 65 ml/g) with an excess of methanolic semicarbazide-acetate solution. The precipitate of semicarbazone is recrystallized from ethanol to give a white powder mp 239-241°. A solution of hydrochloric acid (50 ml) in ethanol (450 ml) is added to the semicarbazone and the mixture is heated at reflux for 1 hr. The clear solution is diluted with water (250 ml) and the... 

An ipso attack on the fluorine carbon position of 4-fIuorophenol at -40 °C affords 4-fluoro-4-nitrocyclohexa-2 5-dienone in addtion to 2-nitrophenol The cyclodienone slowly isomenzes to the 2-nitrophenol Although ipso nitration on 4-fluorophenyl acetate furnishes the same cyclodienone the major by-product is 4 fluoro-2,6-dinitrophenol [25] Under similar conditions, 4-fluoroanisole pnmar ily yields the 2-nitro isomer and 6% of the cyclodienone The isolated 2 nitro isomer IS postulated to form by attack of the nitromum ion ipso to the fluorine with concomitant capture of the incipient carbocation by acetic acid Loss of the elements of methyl acetate follows The nitrodienone, being the keto tautomer of the nitrophenol, aromatizes to the isolated product [26] (equation 20) Intramolecular capture of the intermediate carbocation occurs in nitration of 2-(4-fluorophenoxy)-2-methyIpropanoic acid at low temperature to give the spiro products 3 3-di-methyl-8 fluoro 8 nitro-1,4 dioxaspiro[4 5]deca 6,9 dien 2 one and the 10-nitro isomer [2d] (equation 21)... 

Novel chiral auxiliary, 2 -isopropyl-5 -methylbenzoxazine-spiro-[2.1 ]cyclo-hexan-4-one, and its application to the synthesis of carbapenem antibiotics 97YGK858. 

Trinitrochlorobenzene (76) treated with 1,3-propanedithiole and one equivalent of a base provided compound 479 and its treatment with additional base was reported to provide only small yields of benzodithiepine 480 (74CC672). A more recent work described that good yield (80%) of 480 was obtained by a treatment of 479 with triethylamine in benzene (76ZOR844). Similar treatment of 81 provided first spiro complex 481, which refluxed in acetone in the presence of triethylamine gave good yield of the denitrocyclization product 482 (Scheme 77) (92ZOR1496). 

Condensation of o-phenylenediamine or xV-methyl-o-phenylcne-diamine with alloxan (8) in neutral solution gives the ureides (9) and (10), respectively However, reaction of o-phenylenediamine with 1,3-dimethylalloxan (13) yields quinoxalin-3-one-2-carboxymethyl-amide (14), rather than the dimethyl ureide. Methylation of (9) in acetone in the presence of potassium carbonate gives the spiro-hydantoin (11). 

Chemical Name ( )-[Hydroxy-6-methoxy-5-methyl-11 H-cyclopenta[i,j] -isoquinolinel -7-spiro-1 (2 -cyclohexadiene4-one)... 

Also. 77/-pyrrolo[l,2-fl]azepin-7-ones, e.g. 22, available by the thermal rearrangement of 1-azaspiro[4.5]dcca-l,3,6,9-tetraen-8-ones 21, in trifluoroacetic acid form the deep-blue 7-hy-droxypyrrolo[l,2-tf]azepinium cations, e.g. 23.219 In hot 48 % hydrobromic acid, however, the spiro compound 21 is re-formed. 

Kitsch is the big surf of washed-up popular culture. At Trailer Park, Tom McKay and Andy Spiro, the owners, have assembled it as scientifically as a zoo environment. And on Wednesday, at the nightly happy hour, patrons inhaled it, grazed on it, rolled in it, as if it were a natural habitat. Boxed in by Tammy Faye photos, Dolly Parton dolls, jars of Marshmallow Flulf and the side of a trailer, which forms one wall, the party animals never smelled containment. 

The novel highly substituted spiro[4.4]nonatrienes 98 and 99 are produced by a [3+2+2+2] cocyclization with participation of three alkyne molecules and the (2 -dimethylamino-2 -trimethylsilyl)ethenylcarbene complex 96 (Scheme 20). This transformation is the first one ever observed involving threefold insertion of an alkyne and was first reported in 1999 by de Meijere et al. [81]. The structure of the product was eventually determined by X-ray crystal structure analysis of the quaternary ammonium iodide prepared from the regioisomer 98 (Ar=Ph) with methyl iodide. Interestingly, these formal [3+2+2+2] cycloaddition products are formed only from terminal arylacetylenes. In a control experiment with the complex 96 13C-labeled at the carbene carbon, the 13C label was found only at the spiro carbon atom of the products 98 and 99 [42]. 

Spiroepoxy-endo-tricyclo[5.2.2.026]undeca-4,10-dien-8-one Spiro[4,7-ethano-lH- indene-8,2 -oxiran]-9-one, 3a,4,7,l,7a-tetrahydro- (146924-02-9)... 

Many other reagents for converting alkenes to epoxides,including H2O2 and Oxone , VO(0-isopropyl)3 in liquid C02, ° polymer-supported cobalt (II) acetate and 02, ° and dimethyl dioxirane.This reagent is rather versatile, and converts methylene oxiranes to spiro-epoxides. ° ° One problem with dimethyloxirane is C—H insertion reactions rather than epoxidation. Magnesium monoperoxyphthalate is commercially available, and has been shown to be a good substitute for m-chloroperoxybenzoic acid in a number of reactions. 

Facial selectivities of spiro[cyclopentane-l,9 -fluorene]-2-ones 30a-30e were studied by Ohwada [96, 97]. The carbonyl tz orbital can interact with the aromatic % orbital of the fluorene in a similar manner to spiro conjugation [98-102]. The ketones 30 were reduced to alcohols by the action of sodium borohydride in methanol at -43 °C. The anti-alcohol, i.e., the syn addition product of the reducing reagent with respect to the substituent, is favored in all cases, irrespective of the substituent at C-2 or C-4 of the fluorene ring (2-nitro 30b syn anti = 68 32), 4-nitro... 

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