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本文报导以全乙酰化的1-溴代-α-D-吡喃型糖为原料,立体专一性地合成四个β-型1-硫代糖苷的研究;另以全乙酰化的1-氯代-β-D-吡喃型糖为原料,在氯仿-甲醇溶液中合成了三个α-型1-硫代糖苷。产物均可不经柱层析分离直接以结晶状态析得。论文全面地报导了这些化合物的熔点、比旋光、元素分析值、反应产率,以及碳-13核磁共振谱和付里叶红外光谱数据。通过几对端差异构体的~(13)C-NMR谱发现:它们的C_1位化学位移均有1.5ppm左右的差值。FT-IR光谱中β-异构体在823cm~(-1),α-异构体在775cm~(-1)附近,均有特征吸收峰。其电子束离解源质谱,在70eV或20eV下,α、β-异构体的裂解途径相同,但在高质量区域中碎片峰的强度,则α-异构体大于β-异构体。说明在相同条件下后者优先发生C_1或C_1′的α裂解。
This paper reports the synthesis of four β-1-thioglycosides by stereoselective synthesis of 1-bromo-α-D-glucopyranose as the starting material. Chloro-β-D-glucopyranose as starting materials, three α-1-thioglycosides were synthesized in chloroform-methanol solution. The product can be isolated directly from the crystalline state without separation by column chromatography. The paper reports comprehensively on the melting points, specific rotation, elemental analysis, reaction yields, and carbon-13 nuclear magnetic resonance and Fourier transform infrared spectral data of these compounds. The ~ (13) C-NMR spectra of several pairs of end-isomers showed that their chemical shifts at C 1 were about 1.5 ppm respectively. In the FT-IR spectrum, the β-isomers have characteristic absorption peaks at 823 cm -1 and α-isomers at around 775 cm -1. Their electron beam dissociation mass spectrometry, the cleavage pathway for the α, β-isomers is the same at 70 eV or 20 eV, but the intensity of the fragment peak in high-quality regions is greater than the β-isomer. This indicates that the latter preferentially undergoes α-cleavage of C_1 or C_1 ’under the same conditions.