Reaktion #2146748

Reaktionsgleichung

(4R,5R)-5-(2,4-Dichlorobenzyloxymethyl)-4-(2,4-dichlorobenzyloxy)-2-methoxy-dihydrofuran-3-one

THF

THF

→

(3R,4R,5R)-5-(2,4-Dichlorobenzyloxymethyl)-4-(2,4-dichlorobenzyloxy)-3-ethynyl-2-methoxy-tetrahydrofuran-3-ol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigequenched with saturated NH4Cl (50 ml)
2. 2
   Extraktionextracted with IPAC (2×70 mL)
3. 3
   WaschenThe organic layer is washed with water (50 mL)
4. 4
   Einengenconcentrated

Vorschrift

To a cold (−20° C.) solution of (4R,5R)-5-(2,4-Dichlorobenzyloxymethyl)-4-(2,4-dichlorobenzyloxy)-2-methoxy-dihydrofuran-3-one (9.16 g, 19.07 mmol,) in dry THF (20 mL) is added dropwise a solution of 0.5M alkynylmagnesium bromide (e.g. where R3=H, alkynylmagnesium bromide is ethynylmagnesium bromide) in THF (57.2 mL, 28.6 mmol). The yellow reaction mixture is stirred at the same temperature for 1 h and quenched with saturated NH4Cl (50 ml) and extracted with IPAC (2×70 mL). The organic layer is washed with water (50 mL), concentrated to give (3R,4R,5R)-5-(2,4-Dichlorobenzyloxymethyl)-4-(2,4-dichlorobenzyloxy)-3-ethynyl-2-methoxy-tetrahydrofuran-3-ol (I-4) (R3=H) as dark red oil which is directly used for the next step.

Quelle