Reaction of substituted 1,2,8,9-tetraazadispiro[4.1.4.3]tetradeca-1,8-dien-6-ones and 1,2,8,9-tetraazadispiro[4.1.4.2]trideca-1,8-dien-6-ones with chlorine

Reaction of 4,11-diaryl-1,2,8,9-tetraazadispiro[4.1.4.3]tetradeca-1,8-dien-6-ones and-dispiro[4.1.4.2]trideca-1,8-dien-6-ones with chlorine gives substituted dispirocyclic compounds containing a 3-chloro-1-pyrazoline fragment which loses nitrogen on heating to give spirocyclic chlorocyclopropanes. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 558–566, April, 2008.     

Synthesis and Crystal Structure of Chiral Spiro{1-bromo-4-hydroxy-5-N-cyclohexyl- butyrolactam-6-oxo-dirings[3.1.0]hexane-2,3?-(4?-diphenylcarbinol-5?-menthyloxy-butyrolatone)}

A novel compound of chiral spiro{1-bromo-4-hydroxy-5-N-cyclohexyl-butyro- lactam-6-oxo-dirings[3.1.0]hexane-2,3?-(4?-diphenylcarbinol-5?-menthyloxy-butyrolatone)} was synthesized via tandem nucleophilic substitution reaction under mild conditions, and its structure was determined by IR , 1H NMR, elemental analysis and X-ray diffraction. The crystal structure of this compound is of monoclinic system, space group P21 with a = 9.7356(9), b = 12.2760(12), c = 14.9577(14) ?, β = 101.0300(10)°, Mr = 680.66, Z = 2, V = 1754.6(3) ?3, Dc = 1.288 g/cm3, μ(MoKα) = 1.216 mm-1, F(000) = 716, the final R = 0.0434 and wR = 0.0996.     

Brother versus brother: competitive stabilization of carbocationic centers by flanking cyclopropanes and π‐systems

B3LYP and MP2 quantum chemical calculations on cyclopropylcarbinyl cations fused to various cyclic and polycyclic architectures are described. ‘Competition’ for delocalization between the cyclopropane and other cyclopropanes and/or π‐systems incorporated into the (poly)cyclic framework to which it is fused was assessed, primarily through the use of characteristic geometric perturbations to the cyclopropane substructure. For example, a linear correlation between the orientation of the ‘empty p‐orbital’ at the carbocationic center, which is affected by the nature of the (poly)cyclic framework, and the magnitude of bond elongation in the cyclopropane was observed. Possible bis‐ and trishomoaromaticity of some systems was also evaluated using nucleus independent chemical shift (NICS) and magnetic susceptibility exaltation calculations. Copyright © 2007 John Wiley & Sons, Ltd.     

Ring opening of 1,1-dinitrocyclopropane by addition of C, N, O and S nucleophiles

Nucleophilic ring opening of 1,1-dinitrocyclopropane was studied with diverse C, N, O and S nucleophiles. A series of 3-X-substituted-1,1-dinitropropanes was obtained. Weak nucleophilic tertiary amines were also active in this reaction and afforded zwitterionic compounds.     

Synthesis of Fused [5,5]‐1,2,4‐Triazoles via Tandem Thioimidate Cyclopropane Rearrangement–Cyclization

The synthesis of fused [5,5]‐1,2,4‐triazoles via a tandem cyclopropane rearrangement–cyclization sequence is described. Optimization of the cyclization reaction was achieved thermally using iPrOH as the solvent in the presence of TEA. This method was applied to the preparation of 3‐substituted‐7‐aryl‐pyrrolo‐1,2,4‐triazoles in good to excellent yields.     

新型1,5-二芳基四氢吡咯烷衍生物的合成

以芳基取代环丙烷为原料,与1,3,5-三嗪烷衍生物进行[3+2]环加成反应,高效合成了一系列1,5-二芳基四氢吡咯烷衍生物（3a~3h,其中化合物3f, 3g, 3h为新化合物）,收率70%~97%,其结构经¹H NMR, ¹³C NMR和HR-MS(ESI)表征。     

Intramolecular Photochemistry and Energy Transfer in Molecular Crystals of [2.2] metacyclophane-1-ene and 1,2-diphenylcyclopentene

The intramolecular photocyclisation reactions of the stilbene analogues [2.2] metacyclophane-1-ene (MCPE) and 1,2-diphenylcyclopentene (DPCP) have been investigated in the solid state. In MCPE there is little or no energy transfer through the crystal prior to photoreaction, which occurs in regions of otherwise perfect crystal. This may in large part be due to a slow energy transfer rate because excited molecules relax to a distorted state which is only weakly coupled to its neighbours. In DPCP in the solid state photocyclisation will not occur, presumably for steric reasons. Energy transfer in DPCP is measurably slower than that expected for a rigid lattice.     

Enantioselective Total Synthesis of the Putative Biosynthetic Intermediate Ambruticin J

The family of anti-fungal natural products known as the ambruticins are structurally distinguished by a pair of pyran rings adorning a divinylcyclopropane core. Previous characterization of their biosynthesis, including the expression of a genetically modified producing organism, revealed that the polyketide synthase pathway proceeds via a diol intermediate, known as ambruticin J. Herein, we report the first enantioselective total synthesis of the putative PKS product, ambruticin J, according to a triply convergent synthetic route featuring a Suzuki-Miyaura cross-coupling and a Julia-Kocienski olefination for fragment assembly. This synthesis takes advantage of synthetic methodology previously developed by our laboratory for the stereoselective generation of the trisubstituted cyclopropyl linchpin.     

2-溴甲基-1-苯基环丙甲酸的合成

苯乙腈与环氧氯丙烷在叔丁醇钠的作用下得到2-羟甲基-1-苯基环丙腈,然后在氢氧化钾和盐酸的作用下水解环合得到内酯,再经溴化得到米那普仑中间体2-溴甲基-1-苯基环丙甲酸,总产率为40%。