反应详情

A suspension of H-Ser(Bzl)-OH (2.59 g, 13.28 mmol) in DMF (70 ml) was stirred with Et3N (2.0 ml) and Boc-Thr(Bzl)-OSu (6.0 g, 14.76 mmol) at 0° C for 2 hr and 25° C for 72 hr. The reaction mixture was acidified to about pH 3 with acetic acid and the solvents removed under reduced pressure. The resulting clear oil was extracted into ethyl acetate, washed with 5% AcOH and water, dried (MgSO4) and evaporated to a clear oil. The oil was dissolved in THF (100 ml) and treated with HOSu (1.8 g) and dicyclohexylcarbodiimide (DCC) (3.0 g) for 1.5 hr at 0° C and 25° C for 3 hr. The DCU was removed by filtration and the filtrate evaporated to a clear oil which was crystallized from ETOH, yield 5.3 g (70.4%); mp 112°-113° C; [α]D25 +18.7° (c 1, CHCl3).

1. customthe solvents removed under reduced pressure
2. extractionThe resulting clear oil was extracted into ethyl acetate
3. washwashed with 5% AcOH and water
4. dry with materialdried (MgSO4)
5. customevaporated to a clear oil
6. dissolutionThe oil was dissolved in THF (100 ml)
7. additiontreated with HOSu (1.8 g) and dicyclohexylcarbodiimide (DCC) (3.0 g) for 1.5 hr at 0° C and 25° C for 3 hr
8. customThe DCU was removed by filtration
9. customthe filtrate evaporated to a clear oil which
10. customwas crystallized from ETOH, yield 5.3 g (70.4%)