反应详情

A solution of the crude product of Step 1 (19.2 g, 115 mmol) in acetic anhydride (100 ml) was heated at 110° for 1 h, cooled to room temperature, and evaporated in vacuo. The residue was dissolved in methanol (100 ml) and the solution treated with 4N-NaOH (100 ml). After 2 h, the solution was concentrated in vacuo and the aqueous residue partitioned between dichloromethane (100 ml) and water (100 ml). The chlorinated phase was dried (Na2SO4), and evaporated in vacuo to give an oil which was purified by chromatography (silica; ether) to give the product as crystals (12.0 g).

1. customevaporated in vacuo
2. dissolutionThe residue was dissolved in methanol (100 ml)
3. additionthe solution treated with 4N-NaOH (100 ml)
4. concentrationthe solution was concentrated in vacuo
5. customthe aqueous residue partitioned between dichloromethane (100 ml) and water (100 ml)
6. dry with materialThe chlorinated phase was dried (Na2SO4)
7. customevaporated in vacuo
8. customto give an oil which
9. customwas purified by chromatography (silica; ether)