Reaktion #6609

Reaktionsgleichung

ethyl chloroformate

4-carboxybenzyl 5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl ether

triethylamine

sodium borohydride

hydrochloric acid

→

title compound

Ausbeute 37.7%

4-Hydroxymethylbenzyl 5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl ether

Ausbeute 37.7%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Filtrationthe solid was filtered off
2. 2
   workup.WAITto reach room temperature within 1 h
3. 3
   SonstigeMost of the tetrahydrofuran was removed in a rotary evaporator
4. 4
   Extraktionthe remaining aqueous phase was extracted with chloroform
5. 5
   TrocknenThe organic phase was dried over Na2SO4
6. 6
   Einengenconcentrated
7. 7
   SonstigeFractional crystallization from ethyl acetate

Vorschrift

A solution of 0.97 g (9 mmol) of ethyl chloroformate in 5 ml of tetrahydrofuran was added dropwise to a solution of 3 g (9 mmol) of 4-carboxybenzyl 5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl ether and 0.9 g (9 mmol) of triethylamine in 20 ml of dry tetrahydrofuran at 0° C. The mixture was stirred at 0° C for 30 min, the solid was filtered off, and the filtrate was added dropwise to a solution of 0.83 g (22 mmol) of sodium borohydride in 8 ml of tetrahydrofuran and 8 ml of water. The reaction mixture was then allowed to reach room temperature within 1 h and was then acidified with 1N hydrochloric acid. Most of the tetrahydrofuran was removed in a rotary evaporator, and the remaining aqueous phase was extracted with chloroform. The organic phase was dried over Na2SO4 and concentrated. Fractional crystallization from ethyl acetate, discarding the first fraction, resulted in 1.1 g of the title compound of melting point 108°-109° C.

Quelle