TMSCl as a mild and effective source of acidic catalysis in Fischer glycosidation and use of propargyl glycoside for anomeric protection.

Practical Fischer glycosidation was effected at room temperature or 60 degrees C by using 5 to 10 equiv. of TMSCl. The anomeric propargyl group formed by this method was found to be a versatile new protecting group, being stable in neat TFA but readily cleaved by treatment with Co2(CO)8 and TFA in CH2Cl2 via the formation of an alkyne-Co complex.