Benzaldehyde → 85551-57-1

Temperature

-74 °C

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).

1. temperatureThe beige emulsion is warmed to RT
2. customseparated in a separating funnel
3. extractionThe ether phase is extracted once with 50 ml
4. additionwith twice 30 ml of 2N HCl and is diluted with 300 ml of ether
5. washis then washed with twice 300 ml of water and once with 300 ml of saturated NaCl solution
6. dry with materialdried by means of MgSO4
7. filtrationfiltered
8. customevaporated to dryness on a rotary evaporator
9. customchromatographed (45 g of silica gel, 25 cm length, diameter 2 cm, 10 ml/fraction, 0.3 bar, 1:5 ether/n-hexane) and
10. distillationdistilled (boiling point 150° C./14 mbar)
11. custom1.02 g (79% yield) of a clear, colourless oil are obtained

ORD record

ord-110bcc21da8e47f085f837719be0a47d

Source dataset

uspto-grants-1990_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04914196