Spiro nonane

Thiono-l,3-dithioIan wird an Platin (—1,4 bis —1,6 V) zum Dianion III unter Athy-len-Abspaltung reduziert, das z.B. mit Methyljodid zum /,2-Bis-[methylthio-thiocarbo-nylthio]-athan (IV) bzw. mit 1,2-Dibrom- Oder 1,2-Dijod-athan zum 1,4,6,9-Tetrathia-spiro[4.4]nonan V in DMF/[(C4H9)4N]Br weiterreagiert5 ... 

A chiral diphosphite based on binaphthol, coordinated with rhodium (I) forming a nine-member ed ring, led to an efficient hydroformylation of vinylarenes, although moderate ees were obtained (up to 46%) at mild pressure and temperature reaction conditions.364 Chiral diphosphites and phosphinite-phosphites derived from spiro[4.4]nonane-l,6-diol were synthesized. Using these catalysts in the asymmetric hydroformylation of styrene, high regioselectivity (97%) and... 

This 5-plumba-spiro[4,4] nonane, 99c, is prepared in 9% yield. 

Die relative Konfiguration der drei l,6-Dihydroxy-spiro[4.4]nonane und der beiden l-Keto-6-hydroxy-spiro[4.4]nonane, by E. Maeder (1958). 

Spiro(homocubane-9,9 - diazirine)(Spiro[3//-diazirine-3,9 pentacyclo [4,3,0,02 503 804 7]nonane]), 3127 See related AZO compounds... 

Nieman and Keay198 reported the use of c/.v,c/s-spiro 4,4]nonanc-1, 6-diol as a new chiral auxiliary to be used in asymmetric Diels-Alder reactions. Their best results in a series of reactions between chiral acrylates and cyclopentadiene were obtained when the pivalate ester of ds,ds-spiro[4,4]nonane-l,6-diol was used as the chiral auxiliary. When 318 was treated with cyclopentadiene, the expected endo adduct 319 was obtained with more than 97% de (equation 88). 

Mugford, P.F., Lait, S.M., Keay, B.A. and Kazlauskas, R.J., Enantiocomplementary enzymatic resolution of the chiral auxiliary c7j,c7j-6-(2,2-dimethylpropanamido)spiro-[4.4]nonan- l-ol and the moleuclar basis for the high enantioselectivity of subtilisin Carlsberg. ChemBioChem, 2004, 5, 980-987. 

In the absence of another activated alkene, one molecule of bicyclopropylidene (1), after the opening of a distal bond, underwent formal [3-F2] cycloaddition to a second bicyclopropylidene molecule to give 8-cyclopropylidenedi-spiro[2.0.2.3]nonane (272) (Scheme 61) [2b, 1501. 

Adhering to the same principle, the (< -iodophenyl)diene 129 undergoes a sequence of two intramolecular S-exo-trig carbopalladations (Scheme 34) to yield the benzoannelated spiro[4.4]nonane derivative 129. ... 

Oxaspiropentanes 15 and 18, prepared by the reaction of cyclopentanone and 4-tm-butylcyclo-hexanone, respectively, with diphenylsulfonium 2-methylcyclopropanide, rearranged regiose-lectively with preferential migration of the higher substituted carbon atom. Within the stereoisomeric spiro[3.5]nonan-l-ones 19 formed, a pronounced cis selectivity was observed.62... 

Only a few examples exist where diazocyclopropane has been used for annulations via oxa-spiropentanes. 1,3-Bisdiazopropane reacted with cyclohexanone, probably by previous formation of diazocyclopropane, to give spiro[2.6]nonan-4-one (2, 27%) and spiro[3.5]nonan-l-one (1, 10%).82 83 The latter was formed from the corresponding oxaspiropentane.83 Diazocyclopropane, as generated from /V-cyclopropyl-iV-nitrosourea or /V-cyclopropyl-iV-nitrosocarba-mate, behaves similarly. It reacts with cyclobutanone to give spiro[2.4]heptan-4-one (4, 80%) and spiro[3.3]heptan-l-one (3, 7%).84... 

Methoxycyclopropanemcthanols, as potential precursors of cyclobutanones. are also obtained by addition of 1-methoxy-l-vinyllithium to carbonyl compounds followed by cyclo-propanation of the resulting allylic alcohol. Starting with cyclohexanone the final product was spiro[3.5]nonan-l-one (3).154 Cyclopropanation and rearrangement of an isomeric allylic alcohol 4 yielded spiro[3.5]nonan-2-one (5).15S... 

Nearly all examples of epoxidation of alkylidenecyclobutanes involve 3-chloroperoxybenzoic acid.15 58-70 This is because the conditions are mild, the workup is easy and few byproducts are formed. Generally, dichloromethane or chloroform is used as solvent. Solid sodium hydrogen carbonate is occasionally added to avoid acid-catalyzed rearrangement of the spiro compound. For example, 6-isopropylidene-l,4,4-trimethylbicyclo[3.2.0]heptan-3-one reacted with 3-chloroperoxybenzoic acid and sodium hydrogen carbonate to give 2,2,3, 3, 6-pentamethyl-spiro[3-oxabicyclo[4.2.0]octane-8,2 -oxirane]-4-one (4) in quantitative yield. However, without the use of sodium hydrogen carbonate, substantial amounts of 2,2,6,9,9-pentamethyl-3-oxa-bicyclo[4.3.0]nonane-4,8-dione (5) and 2,2,6,8,8-pentamethyl-3-oxabicyclo[4.3.0]nonane-4,9-dione (6) were also formed.15-64... 

Adam, G., Cesura, A., Jenck, F., Kolczewski, S., Roever, S., Wichmann, J. (F. Hoffmann-La Roche AG) Diaza-spiro[3.5]nonane derivatives, EP970957 (2000). 

Phospha(5-Pv)spiro[4.4]nonane (obsolete) 5As-Phosphaspiro[4.4]nonane (A convention)... 

The allenic ether (204) cyclizes to spiro compounds in the presence of potassium r-butoxide and dicyclohexano-18-crown-6. Acid hydrolysis yields the dihydrofuranone (205). The new carbonyl compound l-oxaspiro[4,4]nonan-4-one can be subjected to another spiroannela-tion sequence. The carbonyl group in (206) has two faces available for addition of a nucleophilic species. Only one product is formed, a cyclopentyl[3]helixane (207). One can in principle continue this reiterative reaction (Scheme 53) (B-81MI31200). 

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