Cyclopentanol → (2-Cyclopentyloxy-5-oxo-tetrahydro-furan-3-yl)-carbamic acid allyl ester

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Reaction Steps

Prepared from 3-allyloxycarbonylamino-4-hydroxy-butyric acid tert-butyl ester as described for 40 using cyclopentanol to afford the title compound as a mixture of diastereomers. Flash column chromatography using hexanes/EtOAc (90/10 to 80/20) afforded the syn diastereomer of the title compound: syn diastereomer 1H NMR (500 MHz, CDCl3) δ 1.5-2.0 (m, 8H), 2.45 (dd, 1H), 2.81 (dd, 0.9H), 3.0 (dd, 0.1H), 4.31 (m, 1H), 4.59 (m, 4H), 5.23 (m, 1H), 5.32 (m, 1H), 5.45 (s, 0.1H), 5.51 (s, 0.9H), 5.92, (m, 1H) ppm; anti diastereomer 1H-NMR (500 MHz, CDCl3) δ 1.50 (m, 2H), 1.67 (m, 6H), 2.36 (d, 1H), 2.8 (dd, 0.08H), 2.96 (dd, 0.92H), 4.13 (m, 1H), 4.25 (m, 1H), 4.55 (br, 2H), 5.20 (d, 1H), 5.30 (m, 2H), 5.43 (s, 0.92H), 5.5 (d, 0.08H), 5.89 (s, 1H) ppm.

Provenance & Evidence