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1.
J Leitich 《Tetrahedron letters》1980,21(32):3025-3028
The relative rates of formation of cis and trans [2+2]cycloadducts of benzyne to cis, trans- and cis, cis-1,5-cyclooctadiene, trans- and cis-cyclooctene are discussed and properties of the adducts (e.g., their unusual hydrogenation) are described.  相似文献   

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Methods are described for the stereospecific conversion of hydrindenone 3 either to the corresponding trans fused or cis fused hydrindanone (1 or 2, respectively.)  相似文献   

3.
All four isomers of substituted 3-alkylthio-4-hydroxybutenes have been synthesised: both the geometry of the double bond and the relative stereochemistry of the two chiral centres are controlled.  相似文献   

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A novel olefin metathesis sequence permits ready access to functionalised cis, syn, cis-tricyclo [6.3.0.02,6] undecane based bis-enones. These bis-enones have been shown to undergo cage cyclisation in sunlight with remarkable ease and efficiency.  相似文献   

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The C4erythro and threo diols (7) and (8) are converted either into the chiral epoxides (13) and (15) or into the enantiomers (14) and (16); the epoxide (13) is used as chiral synthon for the preparation of (3S,4S) 4-methyl-3-heptanol (21).  相似文献   

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Rhodium(III)tetraphenylporphyrin behaves as a sterically hindered cyclopropanation catalyst. Cis-cyclopropanes or “abnormal” products are obtained on reaction with cis-olefins or aromatics.  相似文献   

9.
N-Acyl derivatives of D,L-acosamine and D,L-ristosamine were synthesized with high stereo selectivity utilizing intramolecular Michael addition of γ- and δ-carbomoyloxy-α,β-unsaturated esters.  相似文献   

10.
Intramolecular DIELS-ALDER reactions of requisite trienes led to cis-1-decalones, via an endo intermediate state.  相似文献   

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Head space analysis, GLC retention time data, and solution calorimetry are used to determine the effect of medium on the thermodynamic parameters for the equilibrium (1) ? (2). It is shown that changes in ΔG° and ΔH° can be evaluated for the transfer of the equilibrium from a series of solvents to the gaseous phase which is used as the reference medium.  相似文献   

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1,3,7,9,11,12,14-Heptazapentacene-2,4,8,10 (14H,3H,9H,12H)-tetraones (mixed flavins) were prepared by the cyclization of 1,5-dihydro-8-[N-alkyl-N-(5-nitrouracil-6-yl)-amino-5-deazaflavins with Vilsmeier reagent. The mixed flavins oxidized alcohol under neutral condition in sunlight and a remarkable autorecycling was observed.  相似文献   

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