تفاعل #76055

معادلة التفاعل

lithium aluminum hydride

methyl BOC-D-tyrosinate

→

tert-butyl N-[(1R)-1-hydroxymethyl-2-(4-hydroxyphenyl)ethyl]-carbamate

المردود 55.5%

المذيبات

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe reaction mixture is cooled
2. 2
   تركيزconcentrated under reduced pressure (1 kPa) at a temperature in the region of 60° C
3. 3
   أخرىThe evaporation residue is dried in a desiccator under reduced pressure (0.1 kPa) at a temperature in the region of 40° C.
4. 4
   أخرىis then chromatographed under an argon pressure of 60 kPa on a column of silica gel (particle size 40-63μ; diameter 7 cm; height 24 cm)
5. 5
   غسيلeluting with 10 dm3 of a dichloromethane/methanol mixture (98/2 by volume), 2 dm3 of a dichloromethane/methanol mixture (95/5 by volume) and 2 dm3 of a dichloromethane/methanol mixture (90/10 by volume)
6. 6
   workup.ADDITIONThe fractions containing the expected product
7. 7
   تركيزconcentrated under the above conditions

الإجراء التجريبي

A solution of 29.6 cm3 of lithium aluminum hydride at 1M in tetrahydrofuran is added, with stirring and under an inert atmosphere, at a temperature in the region of 20° C., to a solution of 4.38 g of methyl BOC-D-tyrosinate in 25 cm3 of tetrahydrofuran. After addition of 60 cm3 of tetrahydrofuran, the reaction mixture is heated at a temperature in the region of 70° C. for 3 hours. The reaction mixture is cooled and then concentrated under reduced pressure (1 kPa) at a temperature in the region of 60° C. The evaporation residue is dried in a desiccator under reduced pressure (0.1 kPa) at a temperature in the region of 40° C. and is then chromatographed under an argon pressure of 60 kPa on a column of silica gel (particle size 40-63μ; diameter 7 cm; height 24 cm), eluting with 10 dm3 of a dichloromethane/methanol mixture (98/2 by volume), 2 dm3 of a dichloromethane/methanol mixture (95/5 by volume) and 2 dm3 of a dichloromethane/methanol mixture (90/10 by volume). The fractions containing the expected product are combined and then concentrated under the above conditions. 2.2 g of tert-butyl N-[(1R)-1-hydroxymethyl-2-(4-hydroxyphenyl)ethyl]-carbamate are obtained in the form of a white foam [1H NMR spectrum (400 MHz, (CD3)2SO-d6, δ in ppm): 1.35 (s: 9H); 2.46 (dd, J=14 and 8 Hz: 1H); 2.68 (dd, J=14 and 6 Hz: 1H); from 3.15 to 3.40 (mt: 2H); 3.50 (mt: 1H); 4.61 (mt: 1H); 6.48 (d, J=8.5 Hz: 1H); 6.65 (d, J=8 Hz: 2H); 6.97 (d, J=8 Hz: 2H); 9.11 (broad s: 1H)].

المصدر