Synthetic routes to nucleoside analogs of N-substituted 1,3-thiazolidines

Abstract

Nucleoside analogs, namely 6-benzamido-9-(3-benzoyl-4(R))-methoxycarbonyl-2,2-dimethyl-thiazolidin-5(S)-yl)-9H-purine (7) and 6-chloro-9-[(3-benzoyl-2,2-dimethylthiazolidin-4(R)-yl)methyl]-9H-purine (8), were obtained from 3-benzoyl-5(S)-benzoyloxy-4(R)-methoxycarbonyl-2,2-dimethylthiazolidine (23) and 3-benzoyl-4(R)-hydroxymethyl-2,2-dimethylthiazolidine (24), respectively, the former, by treatment with 6-benzamidochloromercuripurine and titanium tetrachloride in 1,2-dichloroethane and the latter, by treatment with 6-chloropurine, triphenylphosphine, and diethyl azodicarboxylate in tetrahydrofuran. Compound 23 was obtained from 3-benzoyl-4(R)-methoxycarbonyl-2,2-dimethylthiazolidine (13) by treatment with benzoyl peroxide in refluxing benzene whereas compound 24 was obtained from 13 by borohydride reduction. The stereochemistry of the isomeric sulfoxides 18a and 18b, obtained from 13 by treatment with m-chloroperbenzoic acid, was assigned by means of 1Hmr spectroscopy. Reaction of the sulfoxides 18a and 18b under the Pummerer-reaction conditions afforded the rearranged product, 4-benzoyl-3(R)-methoxycarbonyl-5-methyl-3,4-dihydro-2H-1,4-thiazine (20). The chiral shift reagent, tris-[3-(trifluoromethylhydroxymethylene)-d-camphorato]europium(III), was used to confirm the enantiomeric purity of the key intermediates and the product nucleosides. The carbon-13 nmr spectra of the key compounds are reported.

From Amino Acids to Fluorine‐Containing Carbohydrates: De Novo Synthesis of 2‐Amino‐4‐Fluoroxylose and ‐lyxose

“…[13] On the other hand, the photochemically induced rearrangement of these compounds has been shown to furnish the desired monothioacetals in good yields and selectivities. [13] On the other hand, the photochemically induced rearrangement of these compounds has been shown to furnish the desired monothioacetals in good yields and selectivities.…”

Synthesis of “Reversed” Methylenecyclopropane Analogues of Antiviral Phosphonates

“…The isomers were separated by chromatography on silica gel in 46 and 28% yield, respectively. The heterocyclic bases were introduced by Mitsunobu type of alkylation [8][9][10] using phosphonates 10 or 11, triphenylphosphine, diethyl azodicarboxylate (DEAD) and adenine or 2-amino-6-chloropurine in tetrahydrofuran. Reaction of adenine with the Z -isomer 10 gave phosphonate 12a in 47% yield whereas a similar transformation of the E-isomer 11 afforded phosphonate 13a (50%).…”

Synthesis, NMR and ultraviolet spectroscopy of [10] (N6,9)-6-aminopurinophane; calculation of the chemical shifts in the [n](N6,9)-6-aminopurinophane series

“…The procedure used was similar to that of Iwakawa et al (22). To a mixture of 6-chloropurine (4.77 g, 30.86 mmol), triphenylphosphine (8.09 g, 30.84 mmol), and diethyl azidocarboxylate (6.64 g, 6 mL, 30.81 mmol) in 120 mL of dry THF was added a solution of 10-azidodecanol (6.00 g, 30.15 mmol) in 40 mL of THF.…”

“…The procedure used was similar to that of Iwakawa et al (22). Synthesis of N6, N9-Dinonyladenine, 10 6-Chloro-9-nonyl-purine (1 g, 3.57 mmol) was dissolved in a solution of 1-nonyl amine (1.53 g, 2 mL, 10.71 mmol) in 25 mL of acetonitrile and allowed to stir at room temperature for 48 h. The solution was concentrated under reduced pressure and chromatographed on silica gel using ethyl acetate as the eluent.…”