Reaktion #159768

Reaktionsgleichung

lithium

Compound

2-Methoxy-5-((3R,4S,5R,6R)-3,4,5-tris-benzyloxy-6-benzyloxymethyl-2-hydroxy-tetrahydro-pyran-2-yl)-benzaldehyde

6-bromospiro[chromane-2,1′-cyclobutane]

n-butyl lithium

→

[2-methoxy-5-[(3R,4S,5R,6R)-3,4,5-tribenzyloxy-6-(benzyloxymethyl)-2-hydroxytetrahydropyran-2-yl]phenyl]-spiro[chromane-2,1′-cyclobutane]-6-yl-methanone

Ausbeute 65.6%

Lösungsmittel

toluene

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONabove was added to this at −78° C
2. 2
   workup.STIRRINGThis reaction mixture was stirred for 1 h
3. 3
   Sonstigequenched with sat. NH4Cl (10 mL)
4. 4
   Extraktionextracted with ethyl acetate (2×20 mL)
5. 5
   WaschenThe ethyl acetate layer was washed with water, brine
6. 6
   Trocknendried over sodium sulphate
7. 7
   Einengenconcentrated
8. 8
   Sonstigepurified by silica gel column chromatography

Vorschrift

To a stirred solution of 6-bromospiro[chromane-2,1′-cyclobutane] (0.563 g, 2.23 mmol) in THF (3 mL) at −78° C. was added n-butyl lithium (1.45 mL, 2.23 mmol) and stirred for 1 h. Compound obtained in step III (0.3 g, 0.45 mmol) in toluene (3 mL) was cooled to −78° C. and lithium salt prepared above was added to this at −78° C. This reaction mixture was stirred for 1 h, quenched with sat. NH4Cl (10 mL) and extracted with ethyl acetate (2×20 mL). The ethyl acetate layer was washed with water, brine, dried over sodium sulphate, concentrated and purified by silica gel column chromatography to furnish [2-methoxy-5-[(3R,4S,5R,6R)-3,4,5-tribenzyloxy-6-(benzyloxymethyl)-2-hydroxytetrahydropyran-2-yl]phenyl]-spiro[chromane-2,1′-cyclobutane]-6-yl-methanone (0.250 g).

Quelle