P-6 Fucofuranoside法 : β-D-およびβ-L-fucofuranoside誘導体でのpyridine-induced shift差による二級水酸基の絶対配置の決定法(ポスター発表の部)
スポンサーリンク
概要
- 論文の詳細を見る
The available methods for determination of the absolute configuration of secondary alcohols rely on the anisotropy of the substituents which influence directly on the protons of the alcohol moiety. In contrast to this, it seemed possible to use the paramagnetic effect of the solvent pyridine molecule. When the pyridine molecules, solvated to the polar site of the substituent, create an uneven secondary magnetic field, due to the chiral nature of the substituent, it will bring about also an uneven paramagnetic effects on the protons in the alcohol moiety. If the protons in the two segments in the alcohol moiety were distinguished by the magnitude of this pyridine-induced shifts, then that should reflect the absolute configuration of the hydroxyl group. Based on this assumption, we found that the glycosides having β-D- and β-L-fucofuranosyl groups are quite useful for this function. Moreover, the characteristic glycosidation shifts observed for the α- and β-carbons of the aglycon, and the anomeric carbon of the sugar portion, enable to use ^<13>C NMR spectra for the recognition of the absolute configuration as well. Subtraction of the chemical shifts, taken in pyridine, of the β-D-fucofuranoside from those of the β-L-fucofuranoside gives the Δδ values (^1H NMR: δ^<PL>-δ^<PD>; ^<13>C NMR: δ^L_C-δ^D_C) for the proton and carbon atoms situated in the vicinity of the glycoside bond. For the glycosides, spatially arranged as shown in the text, following general rules were derived. (a) In the ^1H NMR spectra, the ΔδS are positive for the right-hand protons and negative for the left-hand protons. (b) If the bulkiness at the β-carbons makes R-type sequence, the Δδ of the α-proton is negative. If it is S-type, the Δδ is positive. (c) In the ^<13>C NMR, the ΔδS of the glycosides, having an equal steric hindrance at β-carbons, are positive for the right-hand β-carbon and negative for the left-hand β-carbon. (d) If the bulkiness at the β-carbon makes R-type sequence, the Δδ of the α-carbon, the right-hand β-carbon, and the anomeric carbon are positive while the Δδ in the left-hand β-carbon is close to zero. In the S-type sequence, the Δδ of the α-carbon, the left-hand β-carbon, and the anomeric carbon are negative while the Δδ in the right-hand β-carbon is close to zero. These rules were found to be effective for the six known chiral alcohols, cholesterol (1), (-)-menthol (2), 1S-endo-(-)-borneol (3), testosterone (4), 4,4-dimethylcholesterol (5) and (+)-furospongin 1(6).
- 1995-09-01
著者
関連論文
- P-6 Fucofuranoside法 : β-D-およびβ-L-fucofuranoside誘導体でのpyridine-induced shift差による二級水酸基の絶対配置の決定法(ポスター発表の部)
- 88(P19) カイラルな3級アルコールへのフコフラノサイド法の適用(ポスター発表の部)
- P-5 ポリハイドロキシステロイドの^C NMRの加成則について(ポスター発表の部)
- 78 軟サンゴ、Sinularia mayiおよびLobohytum strictumから得られたステロイドとセンブラノイドの構造(ポスター発表の部)
- 57 アンダマン、ニコバー産の軟サンゴ、スポンジ、紅藻から得られたステロイドの構造(ポスター発表の部)
- Marine Sterols. XIX. Polyhydroxysterols of the Soft Corals of the Andaman and Nicobar Coasts. (3). Isolation and Structures of Five New C_ Polyhydroxysterols from Two Sclerophytum sp. Soft Corals
- 20 オオイソバナ(gorgonian coral)と数種の軟サンゴからのpolyhydroxysterol類の構造(ポスター発表の部)
- Marine Sterols. XVII. : Polyhydroxysterols of the Soft Corals of the Andaman and Nicobar Coasts. : (2). Isolation and Structures of Three 16β-Hydroxy Steroidal Glycosides from an Alcyonium sp. Soft Coral
- Marine Sterols. XVI. : Polyhydroxysterols of the Soft Corals of the Andaman and Nicobar Coasts. (1). : Isolation of (24S)-24-Methylcholest-5-ene-3β, 25ζ, 26-triol and (24S)-24-Methylcholestane-3β, 5β, 6α, 25-tetrol
- 71(P2-1) 軟サンゴ、オオウミキノコからの新センブラン型ジテルペン類の構造と分子内閉環反応(ポスター発表の部)
- Marine Terpenes and Terpeoids. IX. : Structures of Six New Cembranoids, Sarcophytols F, K, P, Q, R and S, from the Soft Coral Sarcophyton glaucum
- Marine Terpenes and Terpenoids. VIII. : Transannular Cyclization of 3,4-Epoxy-1,7,11-cembratriene Systems
- Marine Terpenes and Terpenoids.VII. : Minor Cembranoid Derivatives, Structurally Related to the Potent Anti-tumor-Promoter Sarcophytol A, from the Soft Coral Sarcophyton glaucum
- 28 軟サンゴ、オオウミキノコからの新センブラン型ジテルペンの構造(口頭発表の部)
- 10-Hydroxypheophytins and a New Norlabdane Diterpene from the Leaves of Cupressus funebris ENDL.
- Studies on the Constituents of Umbelliferae Plants. XVIII. : Minor Constituents of Bupleuri Radix : Occurrence of Saikogenins, Polyhydroxysterols, a Trihydroxy C_ Fatty Acid, a Lignan and a New Chromone
- Marine Terpenes and Terpenoids. V. : Oxidation of Sarcophytol A, a Potent Anti-tumor-Promoter from the Soft Coral Sarcophyton glaucum
- Studies on the Constituents of Umbelliferae Plants. XVII. Structures of Three New Ligustilide Derivatives from Ligusticum wallichii(Organic,Chemical)
- Marine Terpenes and Terpenoids. III. Isolation and Structures of Two Cembrane Diols from the Soft Coral Sinulana mayi(Organic,Chemical)
- Studies on the Constituents of Umbelliferae Plants. XV. Constituents of Cnidium officinale : Occurrence of Pregnenolone, Coniferylferulate and Hydroxyphthalides(Organic,Chemical)
- Marine Terpenes and Terpenoids. X. : Acid-Catalyzed Transannular Cyclization of 11,12-Epoxy-cembranolide
- Marine Terpenes and Terpenoids. VI. : Isolation of Several Plausible Precursors of Marine Combranolides : from the Soft Coral, Sinularia mayi
- Marine Sterols. XXIV. Isolation of 24-Methylenecholestane-1α, 3β, 3α, 6β, 16β-pentol from Sinularia sp. of Soft Coral
- Marine Sterol. XXV.Isolation of 23-Demethylgorgost-7-ene-3β, 5α, 6β-triol and(24S)-Ergostane-3β, 5α, 6β, 7β, 15β-pentol from Soft Corals of the Andaman and Nicobar Coasts
- Marine Terpenes and Terpenoids. XIV. Absolute Configuration and Acid-Catalyzed Transformation of (-)-12,13-Didehydrofurospongin-1 Isolated from an Arabian Sea Sponge, Fasciospongia cavernosa SCHMIDT
- Marine Sterols. XXI. Isolation of (24S)-3β-Hydroxyergost-5-en-21-oic Acid form a Sclerophytum sp. of Soft Coral
- Marine Sterols. XXII. Occurrence of 3-Oxo-4,6,8(14)-triunsaturated Steroids in the Sponge Dvsidea herbacea
- Marine Terpenes and Terpenoids. XIII. Isolation of a New Dihydrofuranocembranoid, Sarcophytonin E, from the Sarcophyton sp. Soft Coral of Okinawa
- Marine Terpenes and Terpenoids. XI. : Structures of New Dihydrofuranocembranoids Isolated from a Sarcophyton sp. Soft Coral of Okinawa
- CONFORMATIONAL STUDY OF THE CEMBRANOID SARCOPHYTOL A, A POTENT ANTI-TUMOR-PROMOTER
- Marine Terpenes and Terpenoids. IV. Isolation of New Cembranoid and Secocembranoid Lactones from the Soft Coral Sinularia mayi
- Studies on the Constituents of Umbelliferae Plants. XVI. Isolation and Structures of Three New Ligustilide Derivatives from Angelica acutiloba(Organic,Chemical)