Dimethyl Sulfoxide → HCID 131725289, compound

Participants

Reaction Steps

Super Grubbs catalyst (2 g) is added to a solution {(2-tert-butoxycarbonylamino-pent-4-enoyl)-[2-(tert-butyl-dimethyl-silanyloxymethyl)-allyl]-amino}-acetic acid methyl ester, 16, (4.1 g, 8.7 mmol) in CH2Cl2(100 mL). The solution is refluxed for 1 hour then DMSO (10 mL) is added and stirring is continued for another 12 hours at room temperature. The solvent is removed in vacuo and the residue purified over silica (EtOAc/hexane) to afford 3.7 g (96% yield) of the desired product. 1H NMR (CDCl3) δ 5.80–5.78 (d, J=6.3 Hz, 1H), 5.65 (bs, 1H), 5.03–4.96 (m, 1H), 4.56–4.48 (m, 2H), 3.98 (s, 2H), 3.98–3.92 (d, J=17.4 Hz, 1H), 3.73 (s, 3H), 3.44–3.38 (d, J=17.7, 1H), 2.74–2.67 (d, d, J=18, 3.3 Hz, 1H), 2.30–2.18 (m, 1H), 1.45 (s, 9H), 0.89 (s, 9H), 0.06 (s, 6H); 13C (CDCl3) δ 172.9, 169.6, 155.2, 135.6, 124.6, 79.7, 66.9, 60.5, 52.4, 50.0, 49.8, 47.6, 33.1, 28.5, 26.0, 18.4,14.4, −5.0; MS 442 (M+H)+.

Provenance & Evidence