Ethyl Acetate → (2'S,3'R,4'S,5'R,6'R)-3',4',5'-tris(benzyloxy)-6'-(benzyloxymethyl)-7-chloro-6-(4-ethylbenzyl)-2-methyl-3',4',5',6'-tetrahydrospiro[chroman-4,2'-pyran]

Participants

Reaction Steps

To a solution of 45 (38 mg, 46 μmol) in dry DCM (1 mL) flushed with argon was added tris(pentafluorophenyl)borane (5 mg, 9.6 μmol). After stirring for 10 min, n-butylsilane (8 μL, ˜2 equiv) was added. Stirring was continued for 3 days. The mixture was directly loaded onto a preparatory TLC plate, developed with 15% EtOAc in petroleum ether to give 46 (21 mg, 56% yield) as a single diastereomer. 1H NMR (300 MHz, CDCl3) δ 7.14-7.31 (m, 19H), 6.81-6.99 (m, 6H), 4.86 (d, J=10.5 Hz, 1H), 4.81 (s, 2H), 4.58 (d, J=12.0 Hz, 2H), 4.45 (d, J=12.0 Hz, 1H), 4.33 (d, J=10.8 Hz, 1H), 4.07-4.16 (m, 2H), 4.04 (d, J=15.0 Hz, 1H), 3.61-3.89 (m, 8H), 2.49 (q, J=7.5 Hz, 2H), 2.15-2.20 (m, 2H), 1.41 (d, J=6.0 Hz), 1.11 (t, J=7.5 Hz, 3H).LCMS m/z 832 (M+Na), 810 (M+H).

Provenance & Evidence