Lithium hydridotris(3-methylbutan-2-yl)borate(1-) → 1,1-Dimethylethyl N-((1S,3R)-3-hydroxycyclopentyl)carbamate

Participants

Reaction Conditions

Reaction Steps

A 1M solution of lithium tris(1,2-dimethylpropyl)borohydride in tetrahydrofuran (1.99 ml) was diluted with tetrahydrofuran (3 ml), cooled to -78° C. and treated dropwise with a solution of (S)-(3-oxocyclopentyl)carbamic acid 1,1-dimethylethyl ester (0.38 g,1.66 mmol) in dry tetrahydrofuran (2 ml) at 0° C. The reaction was stirred for 2h at -78° C. then allowed to warm to room temperature over 1h. Water (2 ml) was added dropwise then the mixture was diluted with water (20 ml) and ethyl acetate (30 ml). The organic phase was washed with water (20 ml), dried (MgSO4) and evaporated to give impure product which was purified by chromatography on flash silica eluting initially with 15% ethyl acetate in cyclohexane and progressing to neat ethyl acetate. Early fractions gave (1S-cis)-(3-hydroxycyclopentyl)carbamic acid 1,1-dimethylethyl ester (0.16 g) as an oil, nmr (d,CDCl3) 1.43(s,9H), 1.50-2.10(m,6H), 3.97-4.10(m,1H), 4.32-4.40(m,1~H), 5.00-5.12(m,1H).

Provenance & Evidence