反応 #6619

反応方程式

THF

diisopropylamine

methyllithium

II

(4S,5S)-2-ethyl-4-methoxymethyl-5-phenyl-2-oxazoline

THF

lithium diisopropylamide

bromide

THF

sodium chloride

compound II

(4S,5S)-2-ethyl-4-methoxymethyl-5-phenyl-2-oxazoline

THF

→

2-(1-methyl-4-isobutylphenyl)-4-methoxymethyl-5-phenyl-2-oxazoline

収率 90.0%

反応条件

後処理

1. 1
   その他is prepared
2. 2
   workup.ADDITIONadded
3. 3
   workup.WAITis continued for half an hour at -75° C.
4. 4
   workup.STIRRINGThe resulting, colorless solution is stirred at this temperature for one hour
5. 5
   その他to reach 20° C
6. 6
   抽出extracted with several portions of petrolether or ether
7. 7
   乾燥dried over Na2SO4 or molecular sieves, (4.0 Å)
8. 8
   workup.DISTILLATIONdistilled in vacuo at 0.1 mm Hg

実験手順

A solution of the compound II (155 g, 0.71 mol) in THF (1.6 L) under nitrogen is cooled to -75° C. in a dry-ice-acetone bath. A solution of 0.8 mol of lithium diisopropylamide, derived from 98 ml of diisopropylamine and 300 ml of 2,3M butylithium (methyllithium) in 750 ml of dry THF is prepared, and added under continuous stirring in the presence of 4.0 Å molecular sieves to the solution of II in dry THF. Stirring is continued for half an hour at -75° C. and 4isobutylphenyliode (bromide) of the amount of 237.6 g (1.95 mol) in 300 ml THF (dry) is added over a period of time of 10 minutes. The resulting, colorless solution is stirred at this temperature for one hour, then subsequently permitted to reach 20° C. The reaction mixture is poured into 3L of saturated aqueous sodium chloride solution, extracted with several portions of petrolether or ether, dried over Na2SO4 or molecular sieves, (4.0 Å) and distilled in vacuo at 0.1 mm Hg to yield 90% of 2-(1-methyl-4-isobutylphenyl)-4-methoxymethyl-5-phenyl-2-oxazoline, having [α]24 -40.5° (c 10.1 in CHCl3) IR (film) 1671 cm-1, NMR (CDCl3, TMS) δ7.33 (s, 5H), 5.33 (d, J=7HZ, 1H), 4.33-3.93 (9, 1H), 3.80-3.33 (m, 2H) 3.43 (3H), 2.87-2.33 (m, 1H), and 2.00-0.68 (m, 12H).

出典