Trimethyl orthoformate → 5,5-Dimethoxypent-2-enal

Temperatur

25 °C

To a mixture of 1-trimethylsilyloxy-1,3-butadiene (14.57 g, 0.1 mol) and trimethyl orthoformate (10 855 g, 0.1 mol) stirring in dichloromethane (500 ml) was added ZnCl2 (1.75 g, 10% mol), and the mixture stirred vigorously at 25° C. for 18 h. The reaction mixture was then poured into saturated aq. NaHCO3 (100 ml), and the organic layer collected. The aqueous layer was reextracted with dichloromethane (100 ml), the combined organic extracts dried over MgSO4, and the solvents removed in vacuo. The resulting brown oil was taken up in hexane/ethyl acetate (1:1) and filtered through a pad of flash silica gel, washing through with a further 400 ml of the solvent mixture. The solvents were removed in vacuo and the crude product Kugelrohr distilled slowly (~0.4 MM Hg/100° C.) to provide the pure enal (7.065 g, 49%)

1. customthe organic layer collected
2. dry with materialthe combined organic extracts dried over MgSO4
3. customthe solvents removed in vacuo
4. filtrationfiltered through a pad of flash silica gel
5. washwashing through with a further 400 ml of the solvent mixture
6. customThe solvents were removed in vacuo
7. distillationthe crude product Kugelrohr distilled slowly (~0.4 MM Hg/100° C.)
8. customto provide the pure enal (7.065 g, 49%)

ORD-Eintrag

ord-6cf8badd7884470db3f9ec7c5fce9cc3

Quelldatensatz

uspto-grants-1993_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05220003