Reaktion #169649

Reaktionsgleichung

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

Lösungsmittel

toluene

toluene

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted 3× with water (270 mL)
2. 2
   workup.ADDITIONwere added
3. 3
   Temperaturcooled to rt
4. 4
   workup.WAITAfter 30 min
5. 5
   Filtrationthe reaction was filtered through a pad of solka-floc
6. 6
   SonstigeThe filtrate was partitioned
7. 7
   Extraktionthe aqueous layer was extracted with additional acetonitrile (810 mL)
8. 8
   EinengenThe combined organic fractions were concentrated in vacuo

Vorschrift

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 5N NaOH, and NAD (0.810 g), PLP (0.810 g), LDH (0.162 g), FDH (1.62 g), and Codexis TA P1 G5 (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.

Quelle