Boron trifluoride etherate → 2-Butyl-2-(3,5-dimethoxy-phenyl)-[1,3]dithiolane

Participants

Reaction Steps

To a stirred solution of Compound 5 (3.52 g, 15.9 mmol) in anhydrous CH2Cl2 (58 ml); was added BF3-Et2O (0.58 ml, 4.8 mmol) and ethane-1,2-dithiol (2.71 g, 28.8 mmol) and stirred at room temperature for 16 h. The organic phase was then extracted with 10% NaOH (20 ml) followed by water and brine. The organic phase was dried, concentrated and the residue resolved over silica gel eluting with EtOAc/hexanes (5:10) to yield 4.50 g (95.2%) of Compound 9 as a colorless oil. Rf=0.51 (hexane:ethyl acetate 9:1); IR (neat) 2955, 1205, 1067 694 cm−1; 1H NMR δ 6.89 (d, J=2.22 Hz, 2H), 6.34 (t, J=2.21 Hz, 1H), 3.81 (s, 6H). 3.40–3.20 (m, 4H), 2.33 (t, J=7.53 2H), 1.31–1.20 (m, 4H), 0.85 (t, J=6.78 Hz, 3H). 13C NMR δ 160.56, 148.04, 106.01, 98.74, 74.58, 55.60, 45.92, 39.33, 30.23, 23.03, 14.13; MS: (ESI, Pos.) m/z 299 (M+).

Provenance & Evidence