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Kiitiro Utimoto Yukio Wakabayashi Yuho Shishiyama Masaharu Inoue Hitosi Nozaki 《Tetrahedron letters》1981,22(43):4279-4280
Title transformation is accomplished by the catalytic action of SnCl2 or BF3·OEt2 Lithio derivative of 2,2-dimethoxyacetonitrile is used as synthetic equivalent of methyl lithioformate. 相似文献
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Treatment of R'CHO with Li[R3BCHCH2] gives an adduct which is believed to be R2BCHR-CH2-CH(OLi)R' (2) or its borate form (3). Oxidation of the adducts with alkaline hydrogen peroxide gives ca. 1:1 mixture of diastereomeric 1,3-alkanediols in good yields. On the other hand, the reaction of BrMg[R3BCHCH2] with R'CHO affords less satisfactory results. Successive treatment of 2 (R = n-Bu, R' = H) with PCl5 and alkaline H2O2 gives HOCHBu-CH2-CH2Cl (6). Treatment of Et2BCHEt-CH2-CHCl-Ph with NaOH aq produces l-ethyl-2-phenylcyclopropane 7. 相似文献
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Cyclopropyltriphenylphosphonium bromide (2a) was conveniently prepared from 3-bromopropyltriphenylphosphonium bromide (1a). The Wittig reaction of cyclopropyltriphenylphosphonium bromide (2a) with carbonyl compounds gave alkylidenecyclopropanes (4, 6 and 7). Successive treatment of 1a with two equivalents of base and carbonyl compounds gave alkylidenecyclopropanes (4 and 5) without isolation of intermediary 2a. 2-Methylcyclopropyltriphenylphosphonium bromide (2b) was prepared and allowed to react with carbonyl compounds. 相似文献
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Lithium trialkylalkynylborates (1) react with oxiranes (2) to give non-isolable intermediates 3 which subsequently afford either γ-hydroxyketones 5, trisubstituted ethylenes of homoallylic alcohol type 6 or a tetrasubstituted ethylene 7 upon appropriate treatment with NaOH/H2O2, AcOH or NaOH/I2, respectively. The reaction of oxiranes with 1 proceeds in high regioselectivity and the resulting homoallylic alcohols 6 are of nearly 100% (E) configuration. A straight chain γ-hydroxyketone 16 is obtained in the reaction of methyloxirane with the ate-complex (1), which has been prepared from lithium acetylide ethylenediamine complex and trihexylborane. 相似文献
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cis-2-Alkylcyclohexanols are obtained stereoselectively upon irradiation of a mixture of cyclohexene and the corresponding trialkylborane in the presence of p-xylene as a sensitizer and upon the successive oxidation of the photolysate with alkaline H2O2. The similar reaction of 1-ethylcyclohexene yields 2,2-dialkylcyclohexanols. Cycloheptene also reacts with the boranes to afford cis-2-alkylcycloheptanols. These reactions are explained by assuming the highly strained trans-cyclohexene or -heptene to be the reactive species. Photochemically produced trans-cyclo-oct-2-enone and cis,trans-cyclo-octa-2,7-dienone react thermally with the bora e to give 3-alkylcyclo-octanone and cis-7-alkylcyclo-oct-2-enone, respectively. Photoreactions of acridine with the boranes result in reductive alkylation, affording 9-alkylacridans in fairly good yields. 相似文献
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Tri-O-benzoyl and tri-O-acetyl derivatives of the title compound are obtained from the corresponding 1-O-acetates in good yields by treatment with cyanotrimethylsilane. 相似文献
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Kiitiro Utimoto Michio Obayashi Yuho Shishiyama Masaharu Inoue Hitosi Nozaki 《Tetrahedron letters》1980,21(35):3389-3392
Triethylaluminium-mediated reaction of cyanotrimethylsilane with 6-methylbicyclo[4.4.0]dec-1-en-3-one affords a mixture of diastereomeric 1,4-adducts. The reaction is kinetically controlled in toluene, whereas thermodynamically in refluxing THF. 4-Methyl-3-penten-2-one and carvone analogously give the respective 1,4-adducts and a conjugated dienone addords the 1,6-adduct in good yield. 相似文献