m-Chloroperbenzoic acid → tert-Butyl 3-(2-(2-((bis(benzyloxy)phosphoryl)oxy)ethoxy)ethoxy)-2,2-dimethylpropanoate

Participants

Reaction Steps

A mixture of tert-butyl 3-(2-(2-hydroxyethoxy)ethoxy)-2,2-dimethylpropanoate (49) (6.87 g, 26.2 mmol), 5-methyl-1H-tetrazole (4.40 g, 52.4 mmol), and dibenzyl diethylphosphoramidite (12.47 g, 39.3 mmol) in THF (66 mL) was allowed to stir at RT for 1.5 h. The solution was cooled to 0° C. and m-CPBA (10.85 g, 47.1 mmol) was slowly added, the mixture was allowed to stir at RT for 16 h. The reaction was diluted with DCM (200 mL) and washed with sat. NaHCO3 (aq.) (4×100 mL), the organic layer was dried (MgSO4), filtered and concentrated in vacuo. The crude product was purified by silica gel chromatography (220 g, 0-40% EtOAc in isohexane) to afford tert-butyl 3-(2-(2-((bis(benzyloxy)phosphoryl)oxy)ethoxy)ethoxy)-2,2-dimethylpropanoate (50) (12.2 g, 89%) as a colourless oil: m/z 545 (M+Na)+ (ES+). 1H NMR (400 MHz, CDCl3) δ: 7.35-7.31 (m, 10H), 5.09-5.00 (m, 4H), 4.13-4.09 (m, 2H), 3.65-3.63 (m, 2H), 3.59-3.52 (m, 4H), 3.39 (s, 2H), 1.41 (s, 9H), 1.11 (s, 6H).

Provenance & Evidence