Reaction #1121759

Reaction equation

(R)-2-ethoxycarbonylmethyl-4-triethylsilyloxy-2-cyclopenten-1-one

sodium hydroxide

→

(R)-2-hydroxycarbonylmethyl-4-triethylsiloxy-2-cyclopenten-1-one

Yield 66.2%

Solvents

phosphate

Conditions

Workup

1. 1
   Otherfinally adjusted to 7.0 upon completion of the reaction
2. 2
   Otherthe Lipase was removed by filtration
3. 3
   ExtractionThe reaction mixture was extracted with 100 ml of ethyl acetate twice
4. 4
   ExtractionThe aqueous layer was extracted twice again
5. 5
   Dryingdried over anhydrous magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   Concentrationconcentrated

Procedure

20 g of (R)-2-ethoxycarbonylmethyl-4-triethylsilyloxy-2-cyclopenten-1-one obtained from Example 35 and 2 g of Candida antarcitica lipase were suspended in 200 ml of phosphate buffer (10 mM, pH 6.5-7.5) and stirred at room temperature. The pH of the solution was maintained by 1N sodium hydroxide solution and finally adjusted to 7.0 upon completion of the reaction and the Lipase was removed by filtration. The reaction mixture was extracted with 100 ml of ethyl acetate twice. The pH of the aqueous layer was further adjusted to 6.0 using a saturated sodium hydrogensulfate solution. The aqueous layer was extracted twice again using 100 ml of ethyl acetate. The organic layers were combined, dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain (R)-2-hydroxycarbonylmethyl-4-triethylsiloxy-2-cyclopenten-1-one (12 g, 65% yield). [α]D: +19.8° (c 1.0, CH3CN);

Source