wt/vol

 

wt/vol

MW

Moles

density

equivs.

yield

I

0.096 g

218.37

0.0004

 

1.0

 

II

0.077 mL

126.93

0.0009

1.455

2.0

 

III

0.125 mL

78.13

0.0018

1.101

4.0

 

IV

0.250 mL

101.19

0.0018

0.726

4.0

 

V

5 mL

-

-

 

 

 

VI

0.083 g

216.35

0.0004

 

 

(87%)

 

Procedure:  25 mL 1-neck flask, stirbar, septum, N2 inlet

                  Dissolved 0.077 mL of oxalylchloride (II) in 4.0 mL of dry CH2Cl2.  Stirred; cooled to -78 C.  Added 0.125 mL of DMSO.  Stirred 10 min.  Added a solution of 0.096 g of alcohol I in 1.0 mL of CH2Cl2.  Stirred 15 min.  Added 0.250 mL Et3N.  After 15 min, warmed to 0 C.  After 10 min TLC showed complete reaction.  The reaction mixture was placed on a silica gel column and the product was isolated by flash chromatography using 25:75 EtOAc-hexanes as eluant.  The product was a clear, colorless oil. 

 

1H NMR (CDCl3, 300 MHz) d 9.06 (d, J = 6.2 Hz, CHO), 3.97 (dd, J = 12.3, 2.3 Hz, H4), 3.77 (dd, J = 12.3, 3.7 Hz, H4), 3.36 (m, H2, H3), 0.87 (s, SiC(CH3)3), 0.06 (s, SiCH3), 0.05 (s, SiCH3). 

 

notes

 

The use of DMSO "activated" by oxalyl chloride has widely become known as the Swern oxidation (see Mancuso, A.J.; Huang, S-L.; Swern, D.  J. Org. Chem.  1978, 43, 2480).  A brief period of premixing of oxalyl chloride and DMSO forms the "activated" salt to which is added the primary or secondary alcohol.

 

The mechanism for the Swern oxidation as first proposed by Corey (see Corey, E.J.; Kim, C.U.  Tetrahedron Lett.  1974, 287) is as follows.