The information given below was retrieved and reworked from the publication: Synthesis of Methoxyfumimycin using 1,2-Addition to Ketimines. Authors: Patrick J. Groß, Caroline E. Hartmann, Martin Nieger and Stefan Bräse. https://doi.org/10.1021/jo902026sA solution of ethyl (2Z)-2-[2-[tert-butyl(dimethyl)silyl]oxy-4-methoxy-5-prop-2-enoxyphenyl]-2-diphenylphosphoryliminoacetate (10.7 g, 18.0 mmol, 1.00 equiv) in toluene (240 mL) was cooled to –78 °C. MeMgBr (3 M in Et2O, 13.4 mL) was added drop wise. After stirring for 3 h, sat. KHSO4 solution (600 mL) was added. The phases were separated; the aqueous layer was extracted with EtOAc (3 × 150 mL). The combined organic extracts were washed with brine (130 mL), dried over Na2SO4 and concentrated under reduced pressure. Flash chromatography (cyclohexane:EtOAc 2:1→2:3) afforded ethyl 2-[5-allyloxy-2-(tert-butyldimethylsilanyloxy)-4-methoxyphenyl]-2-diphenylphosphinoyl-aminopropionate as highly viscous brown oil (7.11 g, 65%). 1H NMR (400 MHz, acetone-D6): δ = 0.24 (s, 3H), 0.33 (s, 3H), 0.94 (s, 9H), 1.14 (t, J = 7.1 Hz, 3H), 1.83 (s, 3H), 3.79 (s, 3H), 4.06 (dq, J = 10.8, 7.1 Hz, 1H), 4.24 (dq, J = 10.8, 7.1 Hz, 1H), 4.38 (mc, 2H), 5.20 (dq, J = 10.5, 1.5 Hz, 1H), 5.39 (dq, J = 17.3, 1.5 Hz, 1H), 6.04 (ddt, J = 17.3, 10.5, 5.3 Hz, 1H), 6.45 (s, 1H), 6.88 (s, 1H), 7.28–7.34 (m, 2H), 7.40-7.56 (m, 4H), 7.62–7.70 (m, 2H), 7.90–7.96 (m, 2H). 13C NMR (100 MHz, acetone-D6): δ = –2.6, 15.3, 20.3, 25.8 (d, JP = 4.1 Hz), 27.6, 57.3, 62.4, 63.1, 72.4, 105.5, 116.5, 118.0, 126.4, 129.9 (d, JP = 12.7 Hz), 130.2 (d, JP = 12.5 Hz), 133.0 (d, JP = 2.6 Hz), 133.4 (d, JP = 2.8 Hz), 133.5 (JP = 9.5 Hz), 133.7 (JP = 9.5 Hz), 136.1 (d, JP = 129.4 Hz), 136.5, 137.1 (d, JP = 131.9 Hz), 143.5, 159.1, 151.5, 176.4 (d, JP = 8.7 Hz). IR (KBr): ν–1= 3335, 2932, 1735, 1611, 1510, 1391, 1245, 1123, 913, 839 cm–1. MS (EI), m/z (%): 609 (16) [M+], 568 (52) [C30H39NO6PSi+], 552 (100) [C29H35NO6SiP+], 536 (78). HRMS (EI) for C33H44NO6SiP: calcd. 609.2676, found 609.2673.
