Benzaldehyde → (1S,3S)-3-methyl-1-phenyl-hex-5-ene-1,3-diol

Temperature

40 °C

Asymmetric tandem aldol-allylation reaction of benzaldehyde to give (1S,3S)-3-methyl-1-phenyl-hex-5-ene-1,3-diol: To a solution of (4R,5R)-2-allyl-2-isopropenyloxy-4,5-bis-(1-methoxy-1-methyl-ethyl)-[1,3,2]dioxasilolane (0.75 mmol) in benzene (0.3 mL) was added benzaldehyde (0.50 mmol). The mixture was heated to 40° C. (oil bath) and stirred at that temperature for 48 hours. The solution was cooled and 1 M HCl (10 mL) was added followed by ethyl acetate (10 mL). The mixture was stirred for 20 min. The layers were separated and the aqueous layer was extracted with ethyl acetate (10 mL). The combined organic layers were washed with saturated aqueous NaHC03 (10 mL) and brine (10 mL), dried (Na2SO4), filtered, and concentrated. Analysis of the residue by HPLC and 1H NMR revealed a 5.5:1 mixture of diastereomers and an enantiomeric excess for the major product of 68%. The residue was purified by chromatography on silica gel to give (1S,3S)-3-methyl-1-phenyl-hex-5-ene-1,3-diol in 70% yield and in 68% ee.

1. temperatureThe solution was cooled
2. stirringThe mixture was stirred for 20 min
3. customThe layers were separated
4. extractionthe aqueous layer was extracted with ethyl acetate (10 mL)
5. washThe combined organic layers were washed with saturated aqueous NaHC03 (10 mL) and brine (10 mL)
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated
9. additiona 5.5:1 mixture of diastereomers
10. customThe residue was purified by chromatography on silica gel

ORD record

ord-3ed2f5d8e00b4eaf84528ed06d800534

Source dataset

uspto-grants-2009_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07534905B2