Red-Al → 4-Methoxy-4-(3-hydroxy-trans-prop-1-enyl)tetrahydropyran

Temperature

0 °C

A solution of 4-methoxy-4-(3-hydroxyprop-1-ynyl)tetrahydropyran (10.8 g, 44.9 mmol), prepared as in step 3, in dry THF (100 mL) was cooled to -75° C., and RED-AL (sodium bis(2-methoxyethoxy)aluminum hydride, Aldrich Chemical Co., 20 mL of 3.4M solution in toluene, 68 mmol) was added under a dry argon atmosphere. The cooling bath was removed and the reaction was warmed to 0° C. and quenched by addition of crushed ice and saturated aqueous NH4Cl. The resulting two-phase mixture was extracted with ethyl acetate (4×90 mL). The combined organic layers were dried over MgSO4, filtered, and concentrated in vacuo. Purification by chromatography on silica gel (100 g, 10% ethyl acetate: hexanes) provided 4-methoxy-4-(3-hydroxy -trans-prop-1-enyl)tetrahydropyran(3.71 g, 34 %) as a colorless oil.

1. customThe cooling bath was removed
2. customquenched by addition of crushed ice and saturated aqueous NH4Cl
3. extractionThe resulting two-phase mixture was extracted with ethyl acetate (4×90 mL)
4. dry with materialThe combined organic layers were dried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customPurification by chromatography on silica gel (100 g, 10% ethyl acetate: hexanes)

ORD record

ord-a5ef738ce61b46948da03a91ac039bae

Source dataset

uspto-grants-1995_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05426111