Nitrogen → HCID 57250906, compound

Participants

Reaction Steps

To a solution of methyl 3β-hydroxy-7-oxochol-5-en-24-oate (2) (5.02 g, 12.5 mmoles) and 2,6-lutidine (3.32 ml, 28.5 mmoles) in CH2Cl2 (23 ml) cooled in an ice bath in a N2 atmosphere was added dropwise with magnetic stirring triisopropylsilyl trifluoromethanesulfonate (4.56 g, 17 mmoles). After 2 hrs, the reaction was diluted with CH2Cl2 (150 ml). It was then washed with cold 2N HCI, washed twice with H2O and then with saturated brine before drying with MgSO4. Evaporation in vacuo and purification of the residue by flash chromatography on silica gel with hexane-EtOAc (10:1) gave 5.88 g of 3 as a colorless syrup. NMR (CDCl3): δ 0.67 (s, 3H, 18-Me); 0.93 (d, 3H, 20-Me); 1.06 (s, 18H, TIPS Me); 1.19 (s, 3H, 19-Me); 3.66 (s, 3H, CO2Me); 3.68 (m, 1H, 3-H); 5.66 (s, 1H, 6-H).

Provenance & Evidence