((2S,4R)-4-(tert-butyldimethylsilyloxy)-6-oxotetrahydro-2H-pyran-2-yl)methyl acetate → (4R,6S)-4-(tert-butyldimethylsilyloxy)-6-(hydroxymethyl)-tetrahydropyran-2-one

Participants

Reaction Conditions

Reaction Steps

(2S,4R)-4-(tert-butyldimethylsilyloxy)-6-oxo-tetrahydro-2H-pyran-2-yl)methyl acetate (7) (8.36 g, 27.64 mmol) and [t-Bu2SnOH(Cl)]2 (1.577 g, 2.764 mmol) are dissolved in MeOH/THF mixture (280 mL). The reaction mixture is stirred at 23-25° C. for 27 h. The solvent is removed under reduced pressure and the remaining residue is purified by silica gel chromatography (elution with t-BuMeO/hexane mixture) to afford a crude product as white solid (5.59 g, 78%). Recrystallization from n-hexane affords (3.90 g, 54%) of (4R,6S)-4-(tert-butyldimethylsilyloxy)-6-(hydroxymethyl)-tetrahydro-pyran-2-one (8) as white needles. M.p.=102° C. (DSC peak). 1H NMR (300 MHz, CDCl3) δ: 4.80 (m, 1H), 4.38 (m, 1H), 3.91 (dd, J=12 Hz, J=3 Hz, 1H), 3.66 (dd, J=12 Hz, J=5 Hz, 1H), 2.60 (d, J=4 Hz, 2H), 2.31 (bs, 1H), 1.97−1.75 (m, 2H), 0.88 (s, 9H), 0.09, 0.08 (2s, 6H). 13C NMR (75 MHz, CDCl3) δ: 170.1, 76.8, 64.7, 63.4, 39.2, 31.9, 25.6, 17.9, −4.9, −5.0.

Provenance & Evidence