反应详情

Lindlar catalyst (palladium on calcium carbonate, poisoned with lead; 60 mg) was added to a solution of alkyne 38 (1.26 g, 8.07 mmol) in 2:1 hexane/EtOAc at 0° C. Hydrogen was bubbled through the reaction mixture until TLC analysis indicated the disappearance of 38 (2-3 h). The mixture was filtered and concentrated to yield 39 was a colorless liquid (1.277 g, 100%): IR (neat) 3410 (br), 3015 (w), 2940 (s), 2860, 1740 (s), 1435,, 1365, 1245, 1205, 1155, 1025, 1000 cm-1 ; 1H NMR (CDCl3) δ 5.66 (ddt, J1 =10.9 Hz, J2 -6.8 Hz, J3 =1.4 Hz, 1H), 5.44 (dtt, J1 =10.9 Hz, J2 =7.5 Hz, J3 =1.3 Hz, 1H), 4.15 (dd, J1 =6.7 Hz, J2 =1.1 Hz, 2H), 3.66 (s, 3H), 2.32 (t, J=7.3 Hz, 2H), 2.12 (dq, J1 =7.5 Hz, J2 =1.1 Hz, 2H), 1.99 (br, 1H), 1.71 (p, J=7.3 Hz, 2H9. A minor amount (ca. 3%) of methyl trans-7-hydroxy-5-heptenoate could be seen in the 1H NMR spectrum at δ 4.09. The longer the reaction proceeded beyond completion, the greater the amount of this product was produced.

1. customHydrogen was bubbled through the reaction mixture until TLC analysis
2. customthe disappearance of 38 (2-3 h)
3. filtrationThe mixture was filtered
4. concentrationconcentrated