Mercuric cyanide → [(2R,3R,4S,5S)-3,4-Dibenzoyloxy-5-cyanooxolan-2-yl]methyl benzoate

Participants

Reaction Steps

A suspension of 2,3,5-tri-O-benzoyl-D-ribofuranosyl bromide (I) (1.98 mol) and dry Hg(CN)2 (750 g; 2.97 mol) (mercury (II) cyanide was dried in vacuo at 140° for 12 hours) in dry CH2Cl2 (10.0 L), was stirred for 16 h at room temperature protected from moisture. The insolubles were collected and discarded. The filtrate was washed in succession with 5% aqueous KI (2×6.0 L) and water (2×6.0 L), dried over Na2SO4 (1.0 kg) and charcoal (35 g), then concentrated in vacuo to an oil. This material was diluted with EtOH (2.0 L) then concentrated in vacuo to an oil. The oil was slowly added to petroleum ether (bp, 63°-75°)-EtOH (21.0 L; 7.0 L) with vigorous stirring. The oil slowly solidified, and after 3 h of stirring, the resulting solid was collected and washed with petroleum ether (bp, 63°-75°) (1.0 L). This material was washed by resuspension (17 h) in EtOH (1.50 L). The off-white colored solid was collected, washed with petroleum ether (bp, 63°-75°) (2×500 ml) then dried to constant weight in vacuo to give 598 g (64°) of product; mp, 77.5°-79°. Additional reactions were carried out to give a total of 4894 g of product suitable for further transformation.

Provenance & Evidence