HCID 10925250, compound → 1807938-02-8

Participants

Reaction Steps

One mole equivalent of (1R,2S)-1,2-dimesyloxy-1,2,3,4-tetrahydronaphthalene was dissolved in 180 volume equivalents of toluene and 30 volume equivalents of 10% aqueous caustic potash was added together with 0.05 weight equivalents of tetrabutylammonium bromide. The mixture was stirred vigorously at ambient temperature for 4 hours when the reaction was judged essentially complete by GLC analysis. The organic layer was separated and washed three times with 0.25 volume equivalents of water. The solvent was removed by vacuum rotary distillation to give a crude brown oily product. The product was purified by column chromatography using Silica Gel 60 and a mixture of hexane and dichloromethane as eluent. The first fraction, after evaporation of the solvent, gave 0.26 mole equivalents of (1S,2R)-1,2-epoxy-1,2,3,4-tetrahydronaphthalene which had an optical rotation [α]D22 =-133° (C=0.21,CHCl3). This compares with the literature value (see below) for (1R,2S)-1,2-epoxy-1,2,3,4-tetrahydronaphthalene of [α]D 32 +133° (C=0.39,CHCl3). Chiral GLC analysis showed the product to be >99.8% enantiomeric excess. Melting point 47°-48° C. J.Chem.Soc.Perkin.Trans I, 1979, 2437 quotes 45°-48° C. 1HNMR: H1=3.95,d,1H; H2=3.75,dt,1H; H3=1.65 and 2.3,m,2H; H4=2.55,m,2H; H5-H8=7.1-7.5,m,4H.

Provenance & Evidence