反应详情

A solution of isopropyl (3-t-butyldimethylsilyloxycyclopentenyl)methylphosphinate (4) (3.4 g, 10.7 mmol) in methanol (30 cm3) was hydrogenated over palladium on carbon (50 mg) at 40 psi for 3 h. The catalyst was removed by filtration through celite which was washed with methanol (3×30 cm3). The solvent was removed in vacuo to yield the desired product in quantitative yield (>90% cis isomer (5) by nmr spectroscopy). Which was used in the next step without further purification (3.4g, 99%) (data for cis isomer only is reported): 1H NMR (300 MHz, CDCl3) δ 0.076 (6H, s), 0.90 (9H, s), 1.32 (6H, d, J=6.1 Hz, OCHCH3), 1.44 (3H, d, J=13.2 Hz, PCH3), 1.63-1.81 (3H, m, C(5)—H, C(5)—H′ and C(1)—H), 1.82-1.99 (2H, m, C(2)—H and C(4)—H), 2.09-2.21 (2H, m, C(2)—H′ and C(4)—H′), 4.26 (1H, m, C(3)—R), 4.65 (1H, m, OCHCH3), 13C NMR (75.46 MHz, CDCl3) δ −4.96 (Si(CH3)2, br. s), 11.07 and 12.28 (PCH3, d, JPC=91.0 and 91.0 Hz), 17.89 (OSiC(CH3)3, s), 23.99 and 24.01 (C5, s), 24.20 (POC(CH3)3, br. d, J=4.0 Hz), 25.68 (OSiC(CH3)3, br. s) 35.78 and 35.81 (C(2), s), 35.91 and 36.11 (C(4), br. s,), 36.11 and 36.17 (C(1), d, JPC=99.6 and 100.7 Hz), 68.25 (POCHCH3, br. d, 2JPOC=6.6 Hz), 73.80 (C(3), d, 3JPC=11.5 Hz), 31 P NMR (121 MHz, CDCl3) δ 57.9, 58.1, MS (CI) m/z 321 (91%) (MH+), 187 (100), 145 (75), (ESI) 321.2012 (M+-C15H34O3PSi requires 321.2015).

1. customThe catalyst was removed by filtration through celite which
2. washwas washed with methanol (3×30 cm3)
3. customThe solvent was removed in vacuo