Diazald → Methyl deoxycholate

Beteiligte Stoffe

Reaktionsschritte

Deoxycholic acid (0.54 g, 1.4 mmol) in THF (10 ml) at 0° C. was treated dropwise with freshly prepared diazomethane in ether (prepared in the usual manner from diazald) until the yellow colour persisted. After 15 minutes at 0° C. the solvent was evaporated to yield a white foam (0.60 g). The compound would not recrystallise, although gas chromatography showed the product to be 99% pure. The product was further purified by preparative silica tlc. (solvent system: EtOAc/CH2Cl2 /AcOH--10:10:1) to afford pure methyl deoxycholate2 (0.45 g, 80%) as a foam: 1H NMR (60 MHz; CDCl3) δ0.67 (3H, s, 18-CH3), 0.92 (3H, s, 18-CH3), 2.18 (2H, s [exchanges on adding D2O], 3α and 12α OH's), 3.2-3.7 (1H, m. 3β-H), 3.65 (3 H, s, --OMe), 3.8-4-1 (1H, m, 12β-H); IR (nujol mull) 3368 (OH's), 1740 (C=O) cm-1 ; MS: Found m/z 388.2951; C25H40O3 (M-H2O) requires 388.2977.

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