4-Toluenesulfonyl chloride → (3S,8S,9S,10R,13S,14S,16S,17R)-17-[(1R,5R)-6-hydroxy-1,5-dimethyl-hexyl]-10,13-dimethyl-2,3,4,7,8,9,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthrene-3,16-diol

Participants

Reaction Steps

To a solution of (25R)-26-hydroxy-16-oxocholesterol (9) (4.52 mmoles in pyridine (20 ml)), cooled in an ice bath, p-toluenesulfonyl chloride (3.44 g, 18.0 mmoles) is added mixture is stirred for 5 hours at room temperature. The reaction mixture is then poured into water and extracted with ether. The organic layer is washed with 2N HCl and water, dried over sodium sulfate, and evaporated under reduced pressure to yield 3.04 g (93%) of (25R)-16β, 26-dihydroxycholesterol 3β, 26-ditosylate (7) as an oil. The product is the same as the one in Example 8.

Provenance & Evidence