Benzaldehyde → 85551-57-1

Participants

Reaction Conditions

Reaction Steps

A solution in 100 ml of diethyl ether of 9.8 mmol of cyclopentadienylallyltitanium bis-(1,2:5,6-di-O-isopropylidene-α-glucofuranose) complex according to Example 1 is cooled to -74° C. by means of a CO2 /acetone bath, and 0.89 ml (8.8 mmol) of freshly distilled benzaldehyde is added. The clear yellow solution is stirred for a further 2 hours at -74° C., and 50 ml of NH4F solution (45% in water) are added. The beige emulsion is warmed to RT and separated in a separating funnel. The ether phase is extracted once with 50 ml and then with twice 30 ml of 2N HCl and is diluted with 300 ml of ether and is then washed with twice 300 ml of water and once with 300 ml of saturated NaCl solution, dried by means of MgSO4, filtered and evaporated to dryness on a rotary evaporator. The crude product is flash chromatographed (45 g of silica gel, 25 cm length, diameter 2 cm, 10 ml/fraction, 0.3 bar, 1:5 ether/n-hexane) and distilled (boiling point 150° C./14 mbar); 1.02 g (79% yield) of a clear, colourless oil are obtained: [α]D =+44.1° (c 6.5, benzene), 91% ee (methods A and B).

Provenance & Evidence