Sodium borohydride → HCID 69057963, compound

Participants

Reaction Steps

To a solution of 6-hydroxy-3,5,7,8-tetramethylspiro[chromene-2,1′-cyclobutan]-4(3H)-one, prepared by reduction of 3-(chloromethylene)-6-hydroxy-5,7,8-trimethylspiro[chromene-2,1′-cyclobutan]-4(3H)-one (see Example 19) (168 mg) in 10 mL of MeOH was added NaBH4 (250 mg). The reaction mixture was allowed to stir at room temperature for 1 hour to give 3,5,7,8-tetramethyl-3,4-dihydrospiro[chromene-2,1′-cyclobutane]-4,6-diol. Subsequently 20 mL of MeOH was added to the reaction mixture, followed by 2 mL of conc. HCl. After 30 min, the reaction mixture was neutralized by adding saturated NaHCO3 and extracted with ethyl acetate. After drying it over anhydrous Na2SO4 and concentrating in vacuo, the residue was purified by flash chromatography eluted with 20% ethyl acetate in hexane to give 113.2 mg of 4-methoxy-3,5,7,8-tetramethyl-3,4-dihydrospiro[chromene-2,1′-cyclobutan]-6-ol as a yellow solid. 1H-NMR (300 MHz, CDCl3) δ=4.83 (s, 1H), 3.08 (s, 2H), 2.46 (s, 3H), 2.28 (s, 3H), 2.26 (s, 3H), 2.28-1.90 (m, 6H) ppm. 13C-NMR (75 MHz, CDCl3) δ=198.6, 149.9, 132.3, 131.8, 129.1, 128.8, 122.7, 57.9, 46.3, 35.1, 16.6, 15.7, 13.7, 13.3 ppm. MS: (m/z)=245.1 (M−OMe+).

Provenance & Evidence