wt/vol

 

wt/vol

MW/conc.

moles

density

equivs.

yield

I

0.156 g

208.25

0.0007

 

1.0

 

II

0.81 mL

1.0 M

0.0008

 

1.1

 

III

6.75 mL

-

-

 

 

 

IV

2.25 mL

-

-

 

 

 

V

0.112 g

164.20

0.0007

 

 

(91%)

 

Procedure:  50 mL 1-neck flask, stirbar, septum, N2 inlet

                  Dissolved 0.156 g of ester I in 6.75 mL of hexanes and 2.25 mL of dry Et2O.  Stirred; cooled to -78 C.  Added 0.81 mL DIBAL (1.0 M in hexanes).  After 10 min, the reaction was quenched with MeOH.  Added ~10 mL of sat. aq. Na/K tartrate, stirred 30 min  and extracted with Et2O.  The organic layer was dried over MgSO4, filtered and the solvent was removed by rotary evaporation.  The product was isolated by flash chromatography on silica gel using 10:90 EtOAc-hexanes as eluant.  The product was a clear, colorless oil.