Cyclopropanes acetylene derivs

Phloeodictyidae 80-100 100-110 Calyx, Oceanapia, Pellina Acetylenic derivatives, cyclopropanic et cyclopropenic sterols for the genus Calyx, a, m-di-thiocyanates, heterocycles. 

Diisobutylaluminum hydride zinc,copper Cyclopropanes from acetylene derivs. 

Hydrofluorination of cyclopropanes. Cyclopropane condensed into an autoclave containing 70%-HF-pyridine, and allowed to react 48 hrs. at room temp. -> propyl fluoride. Y 80% (Synthesis 1973, 779). F. e., also hydrofluorination of ethylene and acetylene derivs. 

Niphatidae 140-150 160-180 Amphimedon, Cribochalina, Niphates Acetylenic derivatives, macro-heterocycles, cyclopropanic fatty acids, S/ P sterols, isonitriles, isothiocyanates, pyridine derivatives (3-alkyl pyridinium), merosesquiterpenes... 

Petrosidae 360-380 500-520 Petrosia, Strongylophora, Xestospongia (= Neopetrosia) Acetylenic derivatives, macro-heterocycles, ve long-chain fatty acids (>4°C), brominated fatty acids, atypical sterols (cyclopropanes, polyhydroxylated, sulfated), atypical glycerol ethers, meroterpenes, aromatic derivatives... 

The majority of preparative methods which have been used for obtaining cyclopropane derivatives involve carbene addition to an olefmic bond, if acetylenes are used in the reaction, cyclopropenes are obtained. Heteroatom-substituted or vinyl cydopropanes come from alkenyl bromides or enol acetates (A. de Meijere, 1979 E. J. Corey, 1975 B E. Wenkert, 1970 A). The carbenes needed for cyclopropane syntheses can be obtained in situ by a-elimination of hydrogen halides with strong bases (R. Kdstcr, 1971 E.J. Corey, 1975 B), by copper catalyzed decomposition of diazo compounds (E. Wenkert, 1970 A S.D. Burke, 1979 N.J. Turro, 1966), or by reductive elimination of iodine from gem-diiodides (J. Nishimura, 1969 D. Wen-disch, 1971 J.M. Denis, 1972 H.E. Simmons, 1973 C. Girard, 1974),... 

The compound 251 decarbonylates on photolysis to bis(4-hydroxyaryl) acetylene 253, which is easily oxidized to the quinonoid cumulene 254. This is also obtained by thermal decarbonylation of the product of oxidation of cyclopropenone 251, the diquinocyclopropanone 252. Likewise, the blue derivative of 3-radialene 256 (a phenylogue of triketo cyclopropane) is formed from tris-(4-hydroxyaryl) cyclopropenium cation 255 by oxidation34. ... 

Relevant examples of 1,2-dialkylcycloalkenes with which to test our conjecture about reaction 12 are disappointingly few. The simplest example of this class of compounds is 1,2-dimethylcyclopropene (24, n = 3, R1 = R2 = Me), and indeed, the requisite thermochemical data are available. Using the derived enthalpy of formation of 1,2-dimethylcyclopropene from Reference 56, we find this reaction to be 32 kJmol-1 endothermic. A posteriori, we are not surprised that this reaction is endothermic. After all, if it is part of the folklore of cyclopropanes that they are said to have olefinic character, then cyclopropenes are also said to have acetylenic character. Indeed, the related transalkylation reaction involving acetylenes... 

Acetylenes and cyclopropenes (37) are related to each other in the same formal way as olefins and cyclopropanes are. Recall that cyclopropanation of ethylene is almost slightly endothermic and the endothermicity was asserted to increase by some (3 2) kJ moT per alkyl group. Cyclopropanation of acetylene to form cyclopropene (37, X = X = H) is endothermic by (48.9 2.6) kJ mol. Cyclopropanation of propyne (monomethy-lacetylene) to form 1-methylcyclopropene (37, X = Me, X = H) has an increased endothermicity of (58.7 1.4) kJ mol. By contrast, the cyclopropanation of 2-butyne (dimethy-lacetylene) using a derived value for the enthalpy of formation of 1,2-dimethylcyclopropene (37, X = X = Me) has an accompanying endothermicity of only 41 kJ moT. We suspect that the last value is in error and so suggest remeasurement of the enthalpy of formation of dimethylcyclopropene as well as measuring the enthalpy of formation of other cyclo-propenes. ... 

The reader will recall the ca k] moT error bars associated with methylating ethylene, acetylene, ethane and propane, even though both the reactant and product hydrocarbons are among the thermochemically best understood of any ever studied. The reader will also recall discrepancies with measured as well as estimated enthalpies of vaporization. Furthermore, error bars associated with measurements of enthalpy of formation are often several kJ moT in magnitude, even for unstrained and therefore comparatively simple hydrocarbons. For example, while the error bars for the enthalpies of formation of cyclohexane and its monomethyl derivative are both under 1 kJmoT, the error bars for all seven of the dimethylcyclohexanes are between 1.7 and 1.9 kJ moT. Perhaps suggestive of considerable sloppiness or uncertainty in the measurements, studies of the enthalpies of many cyclopropanes and other strained species lack error bars. 

The most frequently used metallic catalysts for acyldiazo- and (alkoxycarbonyl)dia-zomethanes are complexes or salts of rhodium, palladium and copper. Alkenylboronic esters A-silylated allylamines and acetylenes are successfully cyclopropanat-ed with diazocarbonyl compounds under catalysis of one of those metal derivatives. Newly developed metallic catalysts for diazoacetic esters include polymer-bound, quantitatively recoverable Rh(II) carboxylate salts ", Cu(II) supported on NATION ion exchange poly-mer ruthenacarborane clusters, Rh2(NHCOCH3)4 which produces cyclopropanes with substantially enhanced trans (anti) selectivity as shown below and (rj -CsHs)... 

The addition reaction has been observed with a variety of olefins, acetylenes, and with cyclopropane 23). Both B2CI4 and B2F4 can add to suitable unsaturated molecules. Unsuccessful attempts to achieve similar reactions with tetraamino and tetraalkoxydiboron compounds and with 1,2-bis-(dimethylamino)-l,2-diethyldiborane(4) have been noted 13, 68). Evidence for formation of bis(boryl) derivatives from the reaction of mixtures of B2[N(CH3)2]4 and BCI3 with olefins has been mentioned (115) the reaction was presumed to involve a mixed dimethylaminochlorodiboron derivative. Lewis base complexes of B2CI4 are unreactive toward olefins (56). 

The reactions of diphenylmethylene and fluorenylidene with olefinic double bonds are not stereospecific. Photochemical or thermal decomposition of diphenyldiazomethane in the presence of alkenes is often accompanied by the formation of a substantial amount of non-cyclic products derived from abstraction-recombination reactions The extent of hydrogen abstraction relative to addition is highly dependent on the substitution pattern of the olefin In contrast, fluorenylidene generated from 9-diazofluorene usually gives cyclopropanes as the major product. Cyclopentadienylidene and its substituted analogues can be generated from the corresponding diazo precursors. They react with olefinic as well as with acetylenic substrates Cycloheptatrienylidene preferentially... 

Phenols can be formed also in rearrangements of small carbocyclic rings, starting from cyclopropane derivatives. For instance, the reaction of benzoylcyclopropene 345 with acetylenes 346 in the presence of 10 mol% of [ClRh(CO)2]2 results in the oxepines 347 and phenols 348. 

Reaction of 1-alkenyltriphenylbismuthonium salts (85) with potassium ferf-butoxide led to the carbene derivatives, 1-alken-l-ylidenes, which can either be trapped by styrene to give cyclopropanes or isomerise to give the corresponding acetylenes. ... 

For chirality transfer via a furan ring transfer reaction of tetrahydrobenzofuranyl allenyl ethers and Claiscn rearrangement see refs 675 and 676. The synthesis of cyclopropanes via Claisen rearrangements of propargylic alcohol derivatives is reported in ref 677 and for acetylene Claisen rearrangements of thio derivatives see refs 678 and 679. 

The first step in the preparation of a cyclopropenium salt is usually the addition of a carbene to an acetylene to provide a cyclopropane derivative. The carbene may come from decomposition of a diazo-compound, as in the example given at the beginning of this chapter [1], or alternatively by treatment with base of a suitable chioro-compound. Thus an alternative preparation of a triphenyl-cyclopropenium salt proceeded as follows [15] ... 

The nickel(O) complex Ni4(CNBu07 catalyzes reduction of acetylenes to olefins, isocyanides and cyanides to amines, as well as cyclotrimerization of acetylene and cyclodimerization of butadiene. Reduction of isocyanides is also catalyzed by other clusters (Chapter 13). Isocyanide copper compounds catalyze addition of CH2CIY (Y = COOR, COR, CN) to olefins leading to the formation of cyclopropane derivatives... 

Substitution of the ethylenic carbons in a conjugated enyne by either an electropositive group in the 3-position or by an electronegative group in the 4-position favors addition to the acetylenic group. G. F. Bettinetti, G. Desimoni, and P. Griinanger, G. 94, 91 (1964) cyclopropane ring from ethylene derivatives in methanol s. F. Wessely and A. Eitel, M. 95, 1577 (1964). 

Carbene chemistry constitutes a particular but challenging field in organic synthesis. Carbenes offer a straightforward access to small rings (cyclopropanes, cyclopropenes) as well as to cycloheptatriene derivatives (the Buchner reaction) from cheap raw material (olefins, acetylenes, benzenic compounds, etc.). 

The allyl ester of acetylene carboxylate 341 was employed as a good precursor for the preparation of cyclopropane-fused 7-butyrolactones 342 (Scheme 1.165) [235]. The reaction progressed in the presence of catalytic amounts of Pd(0Ac>2 and stoichiometric amounts of an oxidant such as PhI(OAc>2. Palladium(ll) and palladium(lV) were presumed to be a catalytic cycle of the reaction. Amide derivative 343, which was readily prepared by the Ugi reaction, gave corresponding cyclopropane-fused 7-butyrolactam 344 in moderate yields (Scheme 1.166) [236]. 

Witten et al. (1973) identified adipic and 3-methyladipic acids and also reported the presence in urine, using GC-MS, of aconitic and isocitric acids in addition to citrate. Mamer et al, (1971) reported the occurrence of several hydroxyaliphatic acids in addition to those already identified by other workers, and Mamer and Tjoa have identified 2-ethylhydracrylic acid in urine derived from isoleucine metabolism (Mamer and Tjoa, 1974). Urine from healthy children and adults may contain low amounts of aliphatic dicarboxylic acids of chain length C4-C8 (Lawson et ai, 1976). Pettersen and Stokke (1973) reported a series of 3-methyl-branched C4-C8 dicarboxylic acids in urine from normal subjects, and Lindstedt and co-workers have identified other dicarboxylic acids with cyclopropane rings and acetylenic bonds as well as a series of cis and trans mono-unsaturated aliphatic dicarboxylic acids (Lindstedt et al., 1974,1976 Lindstedt and Steen, 1975). 

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