Convenient Synthesis of 7-Bromo-tetrahydro-1,5-benzodiazepin-2-ones

Treatment of 5-acyl-2,3,4,5-tetrahydro-1H-1,5-benzodiazepin-2-ones with bromine in the presence of the sulfuric acid afforded products to be brominated exclusively in the aromatic ring at position 7.     

A New Lattice Inclusion Host Involving Double-stranded Columns of Diol Molecules [1]

Abstract

Crystallization of dialcohol 4 from benzene yields an inclusion compound whose crystal structure [(C₁₃H₂₄O₂)₂·(C₆H₆), P2₁/c, a 7.918(2), b 13.505(2), c 14.924(5) Å, β 109.30(1)°, Z 2, R 0.069] shows that the host molecules are present as parallel doubly-stranded columns. Each column is constructed from one strand of (+)-, and a second of (-)-, enantiomers of 4. These two chirally pure strands are linked through a continuous chain of hydrogen bonding …O—H…O—H…O—H… to complete the column, and the benzene guests occupy interstitial sites between the parallel columns.     

2－（2＇－羟基苯基）苯并噁唑在高分子介质中的激发态分子内质子转移和光谱

首次报道了２－（２＇－羟基苯基）苯并ｆ唑（ＨＢＯ）分子在若干高分子固体膜中的电子光谱和激发态分子内质子转移（ＥＳＩＰＴ）的特性，并与溶液体系中的相应特性进行了比较，揭示了新的吸收和发射带，并讨论了高分子基质对这些特性的影响和作用机制。     

Relationship of the Acid-Induced 13C Chemical-Shift Change in the α-Carbon Atom to the Stretching Frequency of the Hydroxy Group in Saturated Alcohols

A good linear relationship was found between the acid-induced ¹³C chemical shift change of the α-carbon atom and the OH stretching frequency of the hydroxy group in some saturated alcohols. The relationship is discussed with model calculations using the CNDO/2 method.

The trifluoroacetic acid-induced ¹³C chemical shift change in the α-carbon atom to the hydroxy group, Δδ¹³c, has been measured for a number, of saturated alcohols in carbon tetrachloride solution and provides information on the relative basicity and its dependence on the structural factor.¹ The free OH stretching frequency, v_OHis known to depend on the structural factor of the substituent._2–5 We reported that a linear relationship exists between the ¹⁷ O chemical shift, δ¹⁷ O, and the OH stretching frequency of the hydroxy group in saturated alchohols, R-OH.⁵ In this case, the ¹⁷O chemical shift change was reported to be governed by the ionization potential.⁶ The ionization potential of R-OH is expected to be correlated with its basicity. Regression analysis for Δδ¹³C was thus carried out for Δδ¹⁷OH reported for 14 and 19 typical alcohols, respectively. In order to explain the experimental results the oretically, we carried out CNDO/2 calculations for a series of methyl-substituted methanols.     

Synthesis of thietane nucleoside with an anomeric hydroxymethyl group

Thietane nucleoside 5 with an anomeric hydroxymethyl group was synthesized via the Pummerer reaction. The stereochemistry of the sulfoxide and the nature of the protecting group had no significant effect on the yield of the reaction. When a hypervalent iodine reagent was used, sulfide 16 with O-benzoyl protecting groups gave the ring-expanded nucleoside 21. Unfortunately, synthesized compound 6 did not exhibit anti-HSV activity.