Carbon Dioxide → 2,5-Methano-5H,9H-pyrimido(2,1-b)(1,5,3)dioxazepin-9-one, 2,3-dihydro-3-(hydroxymethyl)-8-methyl-, (2R,3R,5R)-

Participants

Reaction Conditions

Reaction Steps

To a dried round bottom flask containing thymidine(10.0 g, 41.6 mmol) was added triphenylphosphine (21.8 g, 82.2 mmol) and CH3CN (160 mL). The suspension was cooled to −20° C. ((40:60 iPrOH:H2O) and dry ice). To the reaction mixture was added diisopropylazodicarboxylate (16.8 g, 82.2 mmol) as CH3CN solution (60 mL) dropwise via an addition funnel, over a period of 1 hour. After the addition, the mixture was stirred for an additional 90 minutes at 20° C. The mixture was allowed to warm to 10° C. over a period of 5 hours. The reaction was then quenched with H2O (6 mL) forming a white suspension. The reaction was allowed to stand for 30 minutes and then was filtered. The collected solid was washed with cold CH3CN and dried under vacuum to afford 7.7 g (83% yield) of a white solid. If desired, the solid may be recrystallized in EtOH.

Provenance & Evidence