Isoprene → HCID 67905106, compound

Temperature

-70 °C

In the same manner as in Example 1, a solution of an (R)-binaphthol-dichlorotitanium complex was obtained. This solution was cooled to -70° C. in a dry ice-acetone bath. To this solution were successively added 88 mg (1 mmole) of methyl glyoxylate and 136 mg (2 mmole) of 2-methyl-1,3-butadiene. Reaction was then allowed to proceed at -30° C. for 3 hours, and 10 ml of a sodiumhydrogen carbonate aqueous solution was added to the reaction mixture to terminate the reaction. The reaction mixture was filtered through Celite and then subjected to extraction once with a 20 ml of diethyl ether and twice with 20 ml of ethyl acetate. The extract was dried over anhydrous magnesium sulfate. Thereafter, the solvent was removed by evaporation, and the residue was purified by silica gel column chromatography (200 mesh; developing solvent: hexane/ethyl acetate=10/1), thereby obtaining 34 mg of desired optically active (6R)-6-methoxycarbonyl-4-methyl-5,6-dihydropyran (yield: 22%).

1. customIn the same manner as in Example 1, a solution of an (R)-binaphthol-dichlorotitanium complex was obtained
2. customReaction
3. customto terminate
4. customthe reaction
5. filtrationThe reaction mixture was filtered through Celite
6. extractionsubjected to extraction once with a 20 ml of diethyl ether and twice with 20 ml of ethyl acetate
7. dry with materialThe extract was dried over anhydrous magnesium sulfate
8. customThereafter, the solvent was removed by evaporation
9. customthe residue was purified by silica gel column chromatography (200 mesh; developing solvent: hexane/ethyl acetate=10/1)
10. customobtaining 34 mg

ORD record

ord-1d6e88936f4e4e01b2340c56f9905084

Source dataset

uspto-grants-1992_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05155240