Water → Tert-butyl 2-((1-(trityloxy)but-3-en-2-yl)oxy)acetate

Participants

Reaction Conditions

Reaction Steps

A suspension of tetrabutylammonium hydrogen sulfate (367 g, 1.08 mol, 0.1 equiv.) in toluene (4.63 kg) under nitrogen atmosphere was prepared and cooled down to 0° C. 50% aq. NaOH solution (9.09 kg) was slowly added with the temperature kept under 50° C. Crude mixture from Step 4-(2) (3.95 kg of 1-(trityloxy)but-3-en-2-ol in toluene, total weight 6.34 kg) was slowly added with temperature kept under 15° C. The reaction mixture was stirred for 15 min. tert-Butyl bromoacetate (1.01 kg, 5.19 mol, 0.43 equiv.) was added leading to the formation of a slurry. Water (1 kg) was added then tert-butyl bromoacetate (1.55 kg, 7.95 mol, 0.66 equiv) while maintaining temperature below 30° C. The reaction was left to stir overnight. The reaction was followed by TLC (Rf 0.60 in Heptane/EtOAc 20%). Water (9.72 kg) and 2-methoxy-2-methylpropane (10.4 kg) were added then the reaction mixture was successively washed with water (3.90 kg) and with saturated aq NaCl solution (0.63 kg). The organic phase was then concentrated under reduced pressure to generate a crude mixture (4.70 kg). 1H NMR (500 MHz, CDCl3) δ ppm 7.47 (dt, J=7.9, 3.9 Hz, 6H), 7.27-7.19 (m, 6H), 7.14 (dd, J=14.2, 6.9 Hz, 3H), 5.81-5.70 (m, 1H), 5.28 (d, J=17.2 Hz, 1H), 5.21 (d, J=9.9 Hz, 1H), 4.10-3.94 (m, 3H), 3.34 (dt, J=17.7, 8.8 Hz, 1H), 3.18 (dd, J=9.6, 5.3 Hz, 1H), 1.43 (s, 9H); 13C NMR (125 MHz, CDCl3) δ 169.48, 143.95, 135.69, 128.69, 127.67, 126.86, 118.47, 86.62, 81.07, 80.74, 66.75, 66.41, 28.05.

Provenance & Evidence