A solution of
50 g (0.127 mole) of allyltriphenyltin (Note
1) and (Note
2) in
200 ml. of diethyl ether (Note
3) is prepared in a
1-l. three-necked flask fitted with a reflux condenser, a motor-driven glass sleeve-type stirrer, nitrogen-inlet tube, and a 250-ml. dropping funnel with pressure-equalizing side arm. After the system has been flushed thoroughly with prepurified
nitrogen,
113 ml. of a 1.13N solution of phenyllithium (0.127 mole) in diethyl ether (Note
4) is added rapidly to the stirred
allyltriphenyltin solution. Precipitation of
tetraphenyltin occurs immediately, and the reaction mixture is stirred for 30 minutes in an atmosphere of prepurified
nitrogen. Through the dropping funnel is then added
12.0 g. (0.12 mole) of 4-methyl-2-pentanone (Note
5) in
25 ml. of diethyl ether at such a rate that moderate reflux is maintained. Subsequently the reaction mixture is refluxed for 1 hour, allowed to cool to room temperature, and hydrolyzed by adding 100 ml. of distilled water (Note
6). The solid
tetraphenyltin is filtered (
53.5 g. =
98% yield), and the filtrate is transferred to a
separatory funnel. The aqueous layer is separated and extracted with three
30-ml. portions of ether. The ethereal extracts and the organic layer are combined and dried over anhydrous
magnesium sulfate. After removal of the
ether by distillation at atmospheric pressure, the residue is filtered through a
sintered-glass funnel into a
250-ml. distilling flask and fractionally distilled at reduced pressure using a
vacuum-jacketed Vigreux column equipped with a still head of the total-condensing, partial-takeoff type.
4,6-Dimethyl-1-hepten-4-ol, b.p.
70–71°/20 mm.,
nD20 1.4403, is obtained in
70–75% yield (
12.0–12.8 g.) (Note
7).