tert-Butyl bromoacetate → tert-butyl (1S,2S)-(6-fluoro-2-hydroxy-1-isopropyl-1,2,3,4-tetrahydro-naphthalen-2-yl)acetate

Participants

Reaction Steps

The (1S,2S)-6-fluoro-1-isopropyl-2-[2-(4-toluenesulfonyloxy)ethyl]-1,2,3,4-tetrahydronaphthalene-2-ol, as described in U.S. Pat. No. 4,680,310 (also to Hoffmnann-La Roche), is prepared by reacting (S)-6-fluoro-1-isopropyl-3,4-dihydro-1H-naphthalen-2-one with tert-butyl bromoacetate in the presence of activated magnesium to form tert-butyl (1S,2S)-(6-fluoro-2-hydroxy-1-isopropyl-1,2,3,4-tetrahydro-naphthalen-2-yl)acetate, which is reduced with lithium aluminum hydride to form (1S,2S)-6-fluoro-2-(2-hydroxyethyl)-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-ol, and then reacted with 4-toluenesulfonyl chloride in pyridine to form the (1S,2S)-6-fluoro-1-isopropyl-2-[2-(4-toluenesulfonyloxy)ethyl]-1,2,3,4-tetrahydronaphthalene-2-ol.

Provenance & Evidence