Lithium Hydroxide → 5(S)-(Boc-Amino)-4(S)-hydroxy-6-cyclohexyl-2(R)-[(2,3,4-trimethoxyphenyl)methyl]hexanoic acid

Participants

Reaction Steps

A solution of 600 mg (1.22 mmol) of 5(S)-[1(S)-(Boc-amino)-2-cyclohexylethyl]-3(R)-[(2,3,4-trimethoxyphenyl)methyl]dihydrofuran-2-(3H)-one in 20 ml of dimethoxyethane and 9.9 ml of water is treated, at RT, with 4.9 ml of a 1M solution of lithium hydroxide in water, and this reaction mixture is stirred for 2 h. It is then transferred to a separating funnel and diluted with 60 ml of sat. ammonium chloride solution and 5 ml of a 10% citric acid solution (both being cold); this mixture is then extracted with ethyl acetate and a little THF. The title compound, which is dried under HV and subjected to further processing without being purified, is obtained after washing the organic phase with (cold) saline and drying it over sodium sulfate. IR(CH2 Cl2) inter alia: 3431, 1710, 1602, 1495, 1165 and 1100 cm-1. FAB-MS (M+H)+ =510. HPLC tRet =16.13 min (gradient II).

Provenance & Evidence