Nitrogen → HCID 54170027, compound

Participants

Reaction Steps

Methyl 7-oxo-3β-triisopropylsilyloxychol-5-en-24-oate (3) (5.85 g, 10.5 mmoles) was dissolved with warming in t-BuOH (100 ml). A solution of LiOH.H2O (1.76 g, 41.9 mmoles) in H2O (33 ml) was added, and the two phase mixture was heated at 80° with magnetic stirring in an N2 atmosphere for 2 hrs. Most of the t-BuOH was evaporated in vacuo, the residue-diluted with H2O (~50 ml), and acidified with 2N HCl (22 ml). The gummy suspension was extracted with CH2Cl2 (4 times). The extracts were washed with H2O and saturated brine and dried (MgSO4). Evaporation in vacuo gave 5.38 g of 4 as a gummy solid. NMR (CDCl3): δ0.68 (s, 3H, 18-Me); 0.95 (d, 3H, 20-Me); 1.05 (s, 18H, TIPS Me); 1.20 (s, 3H, 19-Me); 3.68 (m, 1H, 3-H); 5.67 (s, 1H, 6-H).

Provenance & Evidence