反应详情

To a solution of 2.5 g (16.3 mmoles) of 3-hydroxyazetidine-3-carboxylic acid (prepared in Example 6) dissolved in a solution of 2.04 g of sodium hydroxide in 54 ml of water is added 3.34 g (1.2 equivalents) of benzyloxycarbonyl chloride under stirring at room temperature, and the mixture is stirred overnight and then mixed with 10% aqueous sodium hydroxide solution. The resulting alkali solution is washed with ether, adjusted to pH 1 with 10% hydrochloric acid and extracted with ether. The extract is washed with water, dried over sodium sulfate and evaporated under reduced pressure. The residue is crystallized from n-pentane and then recrystallized from ether-n-pentane to yield 3.137 g of 1-benzyloxycarbonyl-3-hydroxyazetidine-3-carboxylic acid as needles, mp. 134°-136° C., in 76% yield.

1. stirringthe mixture is stirred overnight
2. washThe resulting alkali solution is washed with ether
3. extractionextracted with ether
4. washThe extract is washed with water
5. dry with materialdried over sodium sulfate
6. customevaporated under reduced pressure
7. customThe residue is crystallized from n-pentane
8. customrecrystallized from ether-n-pentane