反应详情

To a solution of 4-methylbenzyl-O-benzylphosphinic acid (2, R=4-methylbenzyl) (2.16 g, 8.3 mmol) in THF (15 Ml) was added sodium hydride (0.10 g, 60% dispersion in oil) followed by dibenzyl 2-methylenepentanedioate (3) (3.24 g) at 0° C., and the mixture was stirred at room temperature for 4 hours. The reaction mixture was then diluted with EtOAc (50 Ml) and poured into 1 N Hcl (50 Ml). The organic layer was separated, dried over Na2SO4, and concentrated. This material was purified by silica gel chromatography (hexanes: EtOAc, 4:1 to 1:1) to give 3.41 g of 2,4-di(benzyloxycarbonyl)-butyl(4-methylbenzyl)-o-benzylphosphinic acid (4, R=4-methylbenzyl) as colorless oil (70% yield). Rf 0.61 (EtOAc).

1. additionpoured into 1 N Hcl (50 Ml)
2. customThe organic layer was separated
3. dry with materialdried over Na2SO4
4. concentrationconcentrated
5. customThis material was purified by silica gel chromatography (hexanes: EtOAc, 4:1 to 1:1)