1-(2,6,6-Trimethylcyclohex-3-en-1-yl)but-2-en-1-one → Methyl 2-(4-oxo-4-(2,6,6-trimethylcyclohex-3-enyl)butan-2-ylamino)-3-(4-oxo-4-(2,6,6-trimethylcyclohex-3-enyl)butan-2-ylthio)propanoate

Participants

Reaction Steps

A solution of 1-(2,6,6-trimethylcyclohex-3-enyl)but-2-en-1-one (19.28 g, 100 mmol, 2 equiv.), ethyl diisopropylamine (6.45 g, 50 mmol, 1 equiv.) and L-Cystein methyl ester hydrochloride (8.60 g, 50 mmol, 1 equiv.) in MeOH (120 ml) is heated to reflux during 28 h. The solvent is removed in vacuo and the residue dissolved in methyl t-butyl ether. The solution is washed with dilute aq. NaCl, dried over MgSO4 and concentrated. The residue is purified by chromatography on SiO2 to yield 21.3 g (82%) of the title compound as yellowish, viscous oil.

Provenance & Evidence