تفاعل #155404

معادلة التفاعل

N-Boc-1(R)-amino-2(S)-hydroxy-cyclopentane-4(S)-carboxylic acid methyl ester

imidazole

TBSCl

HCl

→

desired acid

المردود 87.1%

N-Boc-1(R)-amino-2(S)-tert-butyldimethylsilyloxy-cyclopentane-4(S)-carboxylic acid

المردود 87.1%

المذيبات

DCM

isopropanol

chloroform

NaOH

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةby heating at 40° C. for 1 hour
2. 2
   درجة الحرارةThe reaction mixture was cooled to room temperature
3. 3
   أخرىwas quenched with H2O (3 mL)
4. 4
   أخرىThe organic layer was separated
5. 5
   تركيزwas concentrated to dryness
6. 6
   أخرىto yield a residue, which
7. 7
   درجة الحرارةThe reaction was cooled to 0° C.
8. 8
   أخرىthe organic layer was separated
9. 9
   تجفيفdried over Na2SO4
10. 10
    تركيزconcentrated to dryness

الإجراء التجريبي

To a stirring solution of N-Boc-1(R)-amino-2(S)-hydroxy-cyclopentane-4(S)-carboxylic acid methyl ester (0.622 g, 2.40 mmol) in DCM (1.9 mL) was added imidazole (0.164 g, 2.41 mmol), DMAP (0.047 g, 0.35 mmol) and TBSCl (0.363 g, 2.40 mmol) and the reaction was stirred at room temperature for 18 hours, followed by heating at 40° C. for 1 hour. The reaction mixture was cooled to room temperature, and was quenched with H2O (3 mL). The organic layer was separated and was concentrated to dryness to yield a residue, which was dissolved in isopropanol (6 mL) and 1M NaOH (2.9 mL), and the reaction was heated at 60° C. for 1 hour. The reaction was cooled to 0° C. and slowly acidified to pH 3 with 1M HCl (3 mL). After adding chloroform (18 mL), the organic layer was separated, dried over Na2SO4, and concentrated to dryness to yield the desired acid (0.75 g, 2.09 mmol, 87.1% yield).

المصدر