p-Toluenesulfonic acid → 5-chloro-4-(4-ethylbenzyl)-2-((2S,3R,4S,5R,6R)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)-2-(2-methylprop-1-enyl)tetrahydro-2H-pyran-2-yl)phenol

Participants

Reaction Conditions

Reaction Steps

A mixture of p-toluenesulfonic acid (0.136 mg, 0.789 mmol) and 25 (0.65 g, 0.789 mmol) was heated at 65° C. for 7 hours. The reaction mixture was cooled to ambient temperature, after which it was partitioned between 10% NaHCO3 and EtOAc. The organic layer was dried (Na2SO4), filtered, and evaporated. The residue was purified by silica gel column chromatography eluting with 5% EtOAc in petroleum ether to give 26 (490 mg, 75%). 1H NMR (300 MHz, CDCl3) δ 8.83 (s, 1H), 7.20-7.34 (m, 18H), 7.03-7.10 (m, 2H), 6.92-7.00 (m, 7H), 6.85 (s, 1H), 5.59 (s, 1H), 4.77-4.89 (m, 3H), 4.63 (d, J=12.0 Hz, 1H), 4.36-4.44 (m, 3H), 4.00 (d, J=15.6 Hz, 1H), 3.95 (dd, J=5.1, 10.2 Hz, 1H), 3.65-3.80 (m, 6H), 3.52 (dd, J=2.1, 10.5 Hz, 1H), 2.56 (q, J=7.8 Hz, 2H), 1.70 (s, 3H), 1.42 (s, 3H), 1.19 (t, J=7.5 Hz, 3H). LC/MS m/z 846 (M+Na).

Provenance & Evidence