反应详情

Under nitrogen, a stirred solution of 8.7 g (23.5 mmol) of 1,2-dibromo-4,4-di(carboethoxy)cyclopentene (Step 4) in 70 mL of anhydrous THF at -78° C. was treated with 80 mL of diisobutylaluminum hydride (1.5 M in toluene) over a 20 minute period. The reaction was allowed to warm to ambient temperature overnight and was slowly treated with 20 mL of acetone followed by 10 mL of 2.5 N sodium hydroxide. Water (100 mL) was added and the solution extracted 5 times with ethyl acetate. The combined extracts were washed with brine, dried (Na2SO4), and concentrated in vacuo to give 5.7 g (85%) of 1,2-dibromo-4,4-di(hydroxymethyl) cyclopentene (10 in Synthetic Scheme III) as a colorless oil: NMR (CDCl3) d 2.20 (s, 2H), 2.50 (s, 4H), 3.70 (s, 4H) .

1. extractionthe solution extracted 5 times with ethyl acetate
2. washThe combined extracts were washed with brine
3. dry with materialdried (Na2SO4)
4. concentrationconcentrated in vacuo