Bromoform → (2S,4aS,6aR,7R,9R,10aS,10bR)-9-(Bromo)-2-(3-furanyl)-dodecahydro-6a,10b-dimethyl-4,10-dioxo-2H-naphtho[2,1-c]pyran-7-carboxylic acid methyl ester

Participants

Reaction Steps

A mixture of salvinorin B (8a) (0.15 g, 0.38 mmol), triphenylphosphine (0.21 g, 0.80 mmol), and bromoform (0.15 g, 0.45 mmol) in CH2Cl2 (30 mL) was stirred at room temperature overnight. TLC indicated that starting material was still present after 16 h, thus additional triphenylphosphine (0.11 g, 0.42 mmol) and bromoform (0.07 g, 0.21 mmol) were added and the mixture was stirred for an additional 3 h. The solvent was removed under reduced pressure affording a crude solid. The oil was purified by column chromatography (eluent: 30% EtOAc/n-hexanes) to afford 0.10 g (59%) of 36 as a white solid, mp 170-173° C. (EtOAc/n-hexanes); 1H NMR (CDCl3): δ 1.15 (3H, s); 1.48 (3H, s); 1.60 (3H, m); 1.81 (1H, dd, J=2.7, 9.9); 1.95 (1H, dd, J=13.2, 26.1); 2.1 (2H, m); 2.27 (1H, s); 2.47 (1H, dd, J=4.8, 13.2); 2.66 (1H, m); 2.80 (1H, dd, J=3.3, 13.2); 3.70 (3H, s); 3.89 (2H, d, J=2.4); 4.45 (1H, m); 5.55 (1H, dd, J=4.8, 11.7); 6.38 (1H, dd, J=0.9, 1.5); 7.4 (2H, m).

Provenance & Evidence