反応 #6361

反応方程式

diethyl (S)-[1-(t-butyldiphenylsilyloxymethyl)-2-hydroxyethoxy]methylphosphonate

triphenylphosphine

2-[bis-(t-butoxycarbonyl)amino]-9-hydroxy-6-methoxypurine

diethyl azodicarboxylate

→

(S)-2-[bis-(t-butoxycarbonyl)amino]-9-[3-(t-butyldiphenylsilyloxy)-2-(diethoxyphosphorylmethoxy)propoxy]-6-methoxypurine

収率 32.8%

溶媒

THF

反応条件

後処理

1. 1
   温度cooled in ice and under a nitrogen atmosphere
2. 2
   workup.DISSOLUTIONWithin five minutes complete dissolution
3. 3
   その他the ice bath was removed
4. 4
   その他the solution was evaporated to dryness
5. 5
   その他the residue obtained
6. 6
   その他chromatographed on silica gel (initial eluant hexane: ethyl acetate 2:1

実験手順

To a stirred mixture of diethyl (S)-[1-(t-butyldiphenylsilyloxymethyl)-2-hydroxyethoxy]methylphosphonate (540 mg, 1.12 mmol), triphenylphosphine (440 mg, 1.68 mmol) and 2-[bis-(t-butoxycarbonyl)amino]-9-hydroxy-6-methoxypurine (prepared as described in EF-A-319228) (428 mg, 1.12 mmol) in dry THF (20 ml), cooled in ice and under a nitrogen atmosphere, was added dropwise diethyl azodicarboxylate (0.27 ml, 1.68 mmol). Within five minutes complete dissolution had occurred and the ice bath was removed. After 1 hour, the solution was evaporated to dryness and the residue obtained chromatographed on silica gel (initial eluant hexane: ethyl acetate 2:1, then hexane:ethyl acetate in the proportions 1:1, 1:2, 1:3) to yield (S)-2-[bis-(t-butoxycarbonyl)amino]-9-[3-(t-butyldiphenylsilyloxy)-2-(diethoxyphosphorylmethoxy)propoxy]-6-methoxypurine as a colourless glass (310 mg, 32%). 1H NMR: δH [(CD3)2SO] 0.96 (9H, s, t-Bu), 1.18, 1.19 (2×3H, 2×t, J= 7 Hz, (OCH2CH3)2), 1.37 (18H, br.s, 2×t-Bu), 3.7-4.15 (12H, m, CHCH2, (OCH2CH3)2, OCH2P, OCH3), 4.45-4.70 (2H, m, NOCH2), 7.25-7.75 (10H, m, 2×Ph), 8.75 (1H, s, H-8). m/z: (FAB+ve ion, thioglycerol/HCl) 844 (MH+, 4%), 644 (100%).

出典