反应详情

(R)-(−)-3,4-Dihydroxy-5-methyl-5-[4-(2-methylpropyl)phenyl]-2(5H)-furanone was synthesized in, an analogous manner used for the production of (s)-(+)-5-[(1,1′-biphenyl)-4-yl]-3,4-dihydroxy-5-methyl-2(5H)-furanone starting with ethyl 4-isobutylbenzoylformate. (R)-(−)-Phenylglycinol was used to resolve the methyl (R)-(−)-2-(4-isobutylphenyl)propionate enantiomer, of which 1.2 g, (5 mmol) was converted into 190 mg (15% yield) of (R)-(−)-3,4-dihydroxy-5-methyl-5-[4-(2-methylpropyl)phenyl]-2(5H)-furanone as a white crystalline material: mp 180-181° C. dec. (CHCl3/hexanes); [α]25D−137° (c=1.27; MeOH); 1H NMR (acetone-d6) δ 7.44-7.14 (m, 4H), 2.48 (d. 2H, J=7.1 Hz), 1.87-1.82 (m, 1H), 1.83 (s, 3H), 0.88 (d, 6H, J=6.5 Hz). Anal Calcd for C15H18O4: C, 68.68; H, 6.92. Found: C, 68.52; H, 7.01.

1. custom(R)-(−)-3,4-Dihydroxy-5-methyl-5-[4-(2-methylpropyl)phenyl]-2(5H)-furanone was synthesized in, an analogous manner