Stereoselectivity in deoxygenation of 5-hydroxy-5-phosphinyl-hexofuranoses (α-hydroxyphosphonates)

Synthesis of a novel uridine analogue and its use in attempts to form new cyclonucleosides using ring-closing metathesis

“…Yield: 4.0 g of 9 as colorless oil (90%). The physical data were in accordance with those described by Hanaya [21].…”

Synthesis of 2-Acetamido-2,5-dideoxy-5-phosphoryl-D-glucopyranose Derivatives: New Phospha-sugar Analogs of N-Acetyl-D-glucosamine

“…The D-gluco configuration for 13a was assigned on the basis of the small J 4,P (9.9 Hz) and J 4,5 (4.1 Hz) values and the presence of a long range coupling, 4 J 3,P (1.5 Hz) 12,16 (Figure 1). Similarly, the L-ido configuration for 13b was derived from the relatively large J 4,P (18.2 Hz) and small J 4,5 (5.3 Hz) values.…”

“…We describe herein the first synthetic route to the N-acetyl-D-glucosamine phospha-sugar (25), by using our effective procedure 12 to introduce a phosphoryl group onto a sugar skeleton; namely addition of a phosphonate to an appropriate hexos-5-ulose derivative and the subsequent deoxygenation.…”

“…The diastereomeric mixture of 11 was converted to the methoxalyl esters (12) with methoxalyl chloride in the presence of 4-dimethylaminopyridine (DMAP) in 84% yield and then reduced with tributyltin hydride in the presence of AIBN, affording a 72:28 mixture of 5-deoxy products. On structural assignment of the resulting two separable diastereoisomers by 1 H-NMR, it turned out that the major isomer was not the expected 5-deoxy-5-dimethoxyphosphoryl-D-glucose derivative (13a) (23%) but the L-idose isomer (13b) (60%).…”

A New Route for Preparation of 2‐Deoxy‐D‐ribofuranose Phospho Sugar.

“…Moreover, the conversion of 6-nitro group of 6a into its 6-hydroxy derivative and the subsequent conversion into methyl 2,4-dideoxy-4-dimethoxyphosphinoyl-α,β-D-erythro-pentopyranosides (7) required multi-step procedures, thus causing the overall yield of 7 rather low. We describe herein an improved synthesis of 2-deoxy-D-ribofuranose phospho sugar (4) by a new route from D-glucose via the 3-phosphinoy-D-erythritol derivative (13a) obtained by using our alternative procedure; 11,12 i.e., addition of phosphonate to the ketone (11a) and the subsequent deoxygenation.…”