Reaction #42247

Reaction equation

Intermediate 7

methyl 4-methylbenzenesulfonate

(±)-1-(5-methoxy-2,3,6,7,8,9-hexahydro-6,9-ethanonaphtho[1,2-b]furan-2-yl)methanamine

diisopropylethylamine

benzyl chloroformate

→

(±)-benzyl (5-methoxy-2,3,6,7,8,9-hexahydro-6,9-ethanonaphtho[1,2-b]furan-2-yl)methylcarbamate

Yield 93.0%

Conditions

Procedure

Treatment of (±)-1-(5-methoxy-2,3,6,7,8,9-hexahydro-6,9-ethanonaphtho[1,2-b]furan-2-yl)methanamine (2.5 g, 8.45 mmol) with diisopropylethylamine (2.73 g, 21.12 mmol) followed by benzyl chloroformate (1.73 g, 10.14 mmol) generally according to the procedure described for Intermediate 7 provided 3.08 g (93%) of (±)-benzyl (5-methoxy-2,3,6,7,8,9-hexahydro-6,9-ethanonaphtho[1,2-b]furan-2-yl)methylcarbamate as a colorless oil. Chiral HPLC separation of (±)-benzyl (5-methoxy-2,3,6,7,8,9-hexahydro-6,9-ethanonaphtho[1,2-b]furan-2-yl)methylcarbamate (Chiralcel OJ, methanol) provided two fractions. Fraction 1 (Rt=13.252 min, Chiralcel OJ, methanol); Fraction 2 (Rt=18.196 min, Chiralcel OJ, methanol). Treatment of 0.460 g of fraction 1 obtained from the chiral HPLC separation of (±)-benzyl (5-methoxy-2,3,6,7,8,9-hexahydro-6,9-ethanonaphtho[1,2-b]furan-2-yl)methylcarbamate (Chiralcel OJ, methanol) with palladium on carbon (10 wt. %, 0.05 g) generally according to the procedure described for Example 2 provided 0.304 g (88%) of (+)-1-(5-methoxy-2,3,6,7,8,9-hexahydro-6,9-ethanonaphtho[1,2-b]furan-2-yl)methanamine as a white solid, hydrochloride salt. [α]D5=+40.03 (c 9.99 in methanol); mp>220° C.; Anal. calcd. for C16H21NO2HCl: C, 64.97; H, 7.5; N, 4.74. Found: C, 64.62; H, 7.79; N, 4.54.

Source