Formic Acid → (1S,3S)-3-[(tert-Butoxycarbonyl)amino]cyclopentyl formate

Reaction equation

N(C(OCC)=O)=N[C:3](OCC)=[O:4].[CH3:13][C:14]([O:17][C:18](=[O:26])[NH:19][C@H:20]1[CH2:24][CH2:23][C@@H:22]([OH:25])[CH2:21]1)([CH3:16])[CH3:15].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C(O)=O>>[CH3:16][C:14]([O:17][C:18](=[O:26])[NH:19][C@H:20]1[CH2:24][CH2:23][C@H:22]([O:25][CH:3]=[O:4])[CH2:21]1)([CH3:13])[CH3:15]

Participants

Reactant 4

HCID 284Formic Acid

HCID 11776Triphenylphosphine

HCID 220568ethyl N-ethoxycarbonyliminocarbamate

HCID 216370811,1-Dimethylethyl N-((1S,3R)-3-hydroxycyclopentyl)carbamate

Product 1

HCID 86754023(1S,3S)-3-[(tert-Butoxycarbonyl)amino]cyclopentyl formateYield 50.1%

Procedure

Diethyl azodicarboxylate (0.164 ml, 1.23 mmol) was added dropwise to a stirred solution of (1S-cis)-(3-hydroxycyclopentyl)carbamic acid 1,1-dimethylethyl ester (0.124 g, 0.61 mmol), triphenylphosphine (0.323 g, 1.23 mmol) and formic acid (0.046 ml, 1.23 mmol) and the solution was stirred at room temperature for 2h. The solution was then concentrated and purified by column chromatography on flash silica eluting with 10-30% ethyl acetate in cyclohexane to give the title compound (0.07 g) as white needles from diisopropyl ether m.p.84-85° C., [α]D -12.7° (CHCl3 c=0.55%).