Reaction #42201

Reaction equation

Intermediate 7

methyl 4-methylbenzenesulfonate

(±)-1-(2,3,6,7,8,9-hexahydronaphtho[1,2-b]furan-2-yl)methanamine

diisopropylethylamine

benzyl chloroformate

→

(±)-benzyl 2,3,6,7,8,9-hexahydronaphtho[1,2-b]furan-2-ylmethylcarbamate

Yield 79.1%

Conditions

Procedure

Treatment of (±)-1-(2,3,6,7,8,9-hexahydronaphtho[1,2-b]furan-2-yl)methanamine (0.846 g, 4.16 mmol) with diisopropylethylamine (0.592 g, 4.58 mmol) followed by benzyl chloroformate (0.745 g, 4.37 mmol) generally according to the procedure described for Intermediate 7 provided 1.11 g (79%) of (±)-benzyl 2,3,6,7,8,9-hexahydronaphtho[1,2-b]furan-2-ylmethylcarbamate as a white solid. Rf=0.39 (silica, ethyl acetate:hexanes 1:4); mp 88-90° C.; 1H NMR (DMSO-d6) δH 7.49 (t, 1H); 7.33 (m, 4H); 6.87 (d, 1H); 6.50 (d, 1H); 5.02 (s, 2H); 4.76 (m, 1H); 3.20 (m, 3H); 2.83 (dd, 1H); 2.62 (s, 2H); 2.49 (m, 2H); 1.67 (m, 4H). Chiral HPLC separation of (±)-benzyl 2,3,6,7,8,9-hexahydronaphtho[1,2-b]furan-2-ylmethylcarbamate (Chiralcel OJ, isopropanol:hexane 9:1) provided two fractions. Fraction 1 (Rt=11.576 min, Chiralcel OD, isopropanol:hexanes 1:9); Fraction 2 (Rt=14.729 min, Chiralcel OD, isopropanol:hexanes 1:9).

Source