Synthesis and antitumor activity of 7- and 9-(6'-deoxy-.alpha.-L-talofuranosyl)-hypoxanthine and 9-(6'-deoxy-.alpha.-L-talofuranosyl)-6-thiopurine
摘要:
Reaction of 6-deoxy-2,3,5-tris-O-(p-nitrobenzoyl)-L-talofuranosyl bromide (1) with the trimethylsilyl derivative of hypoxanthine, followed by removal of blocking groups, afforded 9- (6) and 7-(6'-deoxy-alpha-L-talofuranosyl)hypoxanthine (7). A study of the published optical rotations and circular dichroic (CD) spectra of pentofuranosylpurines and of (6'-deoxy-beta-D-allo- and -alpha-L-talofuranosyl)purines prepared here suggests that the sign of rotation and the sign of the longer wavelength Cotton effect is determined solely by the configuration of C-1' and its position of attachment to the purine ring. For C-1' R nucleosides, the sign is negative for N-9-linked purine nucleosides and positive for the N-7-linked isomers, and vice versa for C-1'S purine nucleosides. Reaction of 1 with the trimethylsilyl derivative of 6-chloropurine afforded 4, which upon treatment with thiourea and deblocking yielded 9-(6'-deoxy-alpha-L-talofuranosyl)-6-thiopurine (8). Unlike the previously prepared 7-(6'-deoxy-beta-D-allofuranosyl) hypoxanthine which strongly inhibited purine nucleoside phosphorylase, compounds 6-8 did not inhibit this enzyme. Compound 8 significantly inhibited the growth of L1210 tumor cells in vitro and in vivo.
synthesis of bicyclic perhydrofuropyran nucleosides as N-analogues of the naturally occurring malayamycin A. Formation of the N-nucleosides relied on the activation of thioglycosides, proceeding via sulfonium intermediates. Ring closure metathesis was used in two approaches to build the bicyclic dioxa heterocycle. Another approach relied on the use of a sugar precursor and cyclization to the bicyclic thioglycoside
Silica Sulfuric Acid (SSA) as a Highly Efficient Heterogeneous Catalyst for Persilylation of Purine and Pyrimidine Nucleobases and Other <i>N</i>-Heterocycles Using Hmds
Purine and pyrimidine nucleobases and other N-heterocycles have been silylated with HMDS in excellent yields in the presence of a catalytic amount of silica sulfuric acid (SSA) as a heterogeneous catalyst. SSA utilizes a shorter reaction time and higher yields of silylated nucleobases. SSA is reusable for several times without a decrease in reactivity or yield of silylated adducts.
Kraska, Burckhard; Lichtenthaler, Frieder W., Chemische Berichte, 1981, vol. 114, # 5, p. 1636 - 1648
作者:Kraska, Burckhard、Lichtenthaler, Frieder W.
DOI:——
日期:——
Synthesis of hypoxanthine, guanine, and 6-thiopurine nucleosides of 6-deoxy-D-allofuranose
作者:Victor Nelson、Hassan S. El Khadem、Bertwell K. Whitten、Debra Sesselman
DOI:10.1021/jm00361a023
日期:1983.7
Hypoxanthine, guanine, and 6-thiopurine nucleosides of 6-deoxy-D-allofuranose have been prepared as potential antitumor agents. Thus, reaction of 6-deoxy-beta-D-allofuranosyl bromide (1) with the trimethylsilyl derivatives of hypoxanthine and guanine afforded mixtures of the 9- and the 7-substituted bases, which were separated and deblocked with ammonia to give 9-(6'-deoxy-beta-D-allofuranosyl)hypoxanthine (6), 7-(6'-deoxy-beta-D-allofuranosyl)hypoxanthine (7), 9-(6'-deoxy-beta-D-allofuranosyl)guanine (8), and 7-(6'-deoxy-beta-D-allofuranosyl)guanine (9). The two nucleosides with the purine joined at the N-9 position, namely, 6 and 8, are easily distinguished from the other two nucleosides (7 and 9), having N-7 junctions, by their NMR spectra. Reaction of 1 with the trimethylsilyl derivative of 6-chloropurine afforded 10, which upon treatment with thiourea and deblocking gave 9-(6'-deoxy-beta-D-allofuranosyl)-6-thiopurine (12). The hypoxanthine and guanine nucleosides showed no inhibition of mouse leukemia L1210 when tested in vivo, but the thiopurine nucleoside 12 showed strong inhibition of growth of L1210 both in vivo and in vitro. Compound 7 strongly inhibited purine nucleoside phosphorylase (KI = 8.8 X 10(-5) M), while compounds 8, 9, 6, and 12 were inactive.
Analogs of purine nucleosides. 3. Alkoxyalkylation of hypoxanthine by the silyl method
作者:M. A. Madre、�. �. Liepin'sh、R. A. Zhuk、O. V. Sakhartova、M. Yu. Lidak