反应详情

A solution of LiOH (400 mg, 16.7 mmol, 2.15 eq) in dry DMF (44 mL) containing activated 4 Å molecular sieves was stirred vigorously for 20 min, treated with Phe-Ot-Bu*HCl (2 g, 7.76 mmol, 1 eq), stirred for 45 min, treated with a solution 80% propargyl bromide (1.4 mL, 9.4 mmol, 1.21 eq) in toluene, stirred for 16 h and filtered through a pad of Celite™, which was washed with EtOAc (Cho, J. H. and B. M. Kim, Tetrahedron Lett. 2002, 43 1273-1276). The filtrate was washed three times with water, dried over MgSO4 and the volatiles were evaporated to provide an oil, which was purified by chromatography on silica gel using 30% EtOAc in hexane as eluent. Evaporation of the collected fractions gave ester 41 as yellow oil (1.66 g, 83%): Rf=0.53 (8:2 hexane/EtOAc); 1H NMR (400 MHz, CDCl3) δ 7.32-7.28 (m, 2H), 7.24 (m, 3H), 3.62 (t, J=6.9 Hz, 1H), 3.47-3.36 (m, 2H), 2.96 (m, 2H), 2.20 (m, 1H), 1.77 (s, 1H), 1.39 (s, 9H); 13C NMR (300 MHz, CDCl3) δ 172.9, 137, 129.2, 128.1, 126.4, 81.3, 81.0, 71.6, 61.5, 39.4, 36.5, 27.8. IR (thin film) v 3297, 2981, 2942, 1723, 1370, 1152, 700 cm−1; HRMS (LC-ESI) m/z calcd for C16H22NO2 [MH]+ 260.1645. Found 260.1634.

1. stirringstirred for 45 min
2. stirringstirred for 16 h
3. filtrationfiltered through a pad of Celite™, which
4. washwas washed with EtOAc (Cho, J. H. and B. M. Kim, Tetrahedron Lett. 2002, 43 1273-1276)
5. washThe filtrate was washed three times with water
6. dry with materialdried over MgSO4
7. customthe volatiles were evaporated
8. customto provide an oil, which
9. customwas purified by chromatography on silica gel using 30% EtOAc in hexane as eluent
10. customEvaporation of the collected fractions