(S)-2-Cyclopentyloxycarbonylamino-3,3-dimethyl-butyric acid → (5S,8S)-methyl-3-(3-chlorophenyl)-7-((S)-2-(cyclopentyloxycarbonylamino)-3,3-dimethylbutanoyl)-2-oxo-1-oxa-3,7-diazaspiro[4.4]nonane-8-carboxylate

Participants

Reaction Steps

Following the same procedure as Example 1 step G using (5S,8S)-methyl-3-(3-chlorophenyl)-2-oxo-1-oxa-3,7-diazaspiro[4.4]nonane-8-carboxylate (30 mg, 97 μmol) and (S)-2-(cyclopentyloxycarbonylamino)-3,3-dimethylbutanoic acid (28 mg, 116 μmol, 1.2 eq.) gave 22 mg (41 μmol) of (5S,8S)-methyl-3-(3-chlorophenyl)-7-((S)-2-(cyclopentyloxycarbonylamino)-3,3-dimethylbutanoyl)-2-oxo-1-oxa-3,7-diazaspiro[4.4]nonane-8-carboxylate (C3). 1H NMR (300 MHz, CDCl3) 7.35-6.8 (m, 4H), 5.21-5.06 (m, 1H), 4.86 (m, 1H), 4.55-3.56 (m, 8H), 2.65-2.48 (m, 1H), 2.0 (m, 1H), 1.7-1.1 (m, 9H), 0.9-0.7 (m, 9H).

Provenance & Evidence