反応 #494369

反応方程式

NAD

Potassium carbonate

4,4-dimethoxydihydro-2H-pyran-3(4H)-one

NaOH

potassium dihydrogenphosphate

sodium formate

L-Alanine

→

(3S)-4,4-dimethoxytetrahydro-2H-pyran-3-amine

溶媒

toluene

toluene

acetonitrile

反応条件

後処理

1. 1
   抽出extracted 3× with water (270 mL)
2. 2
   workup.ADDITIONwere added
3. 3
   温度cooled to rt
4. 4
   workup.WAITAfter 30 min
5. 5
   ろ過the reaction was filtered through a pad of solka-floc
6. 6
   その他The filtrate was partitioned
7. 7
   抽出the aqueous layer was extracted with additional acetonitrile (810 mL)
8. 8
   濃縮The combined organic fractions were concentrated in vacuo

実験手順

A solution of 4,4-dimethoxydihydro-2H-pyran-3(4H)-one (172 g, 1.07 mol, see Example 1) in 310 mL of toluene was stirred in toluene for 30 min, then extracted 3× with water (270 mL). To the aqueous solution was added potassium dihydrogenphosphate (14.1 g, 0.104 mol), sodium formate (55.1 g, 0.810 mol), and L-Alanine (72.2 g, 0.810 mol). The pH was adjusted to 7.8 with 5 N NaOH, and NAD (0.810 g), PLP (0.810 g), LDH (0.162 g), FDH (1.62 g), and Codexis TA P1G5 (4.05 g) were added. The mixture was heated to 45° C. for 12 h, then cooled to rt. Potassium carbonate (324 g, 2.34 mol) was added, and after 30 min, the mixture was diluted with acetonitrile (810 mL). After 30 min, the reaction was filtered through a pad of solka-floc. The filtrate was partitioned and the aqueous layer was extracted with additional acetonitrile (810 mL). The combined organic fractions were concentrated in vacuo to provide crude (3S)-4,4-dimethoxytetrahydro-2H-pyran-3-amine.

出典