Epoxy compounds glycidol

There are often problems encountered in the isolation of low molecular weight epoxy-alcohols such as the parent compound glycidol, due to their water solubility. Such difficulties can be avoided by derivatisation in situ as the p-toluenesulphonate or p-nitrobenzenesulphonate ester and this procedure is illustrated in the application of the Sharpless oxidation to prepare (-)-propranolol described in section 7.4.2. 

The prototype for this structural class is 2-methyl-2-propen-l-ol (methallyl alcohol) from which asymmetric epoxidation generates optically active 2-methyloxiranemethanol. Like glycidol, 2-methyloxiraiie-methanol has been difficult to obtain by stoichiometric asymmetric epoxidation, but with the use of the catalytic version reasonable quantities now are produced and the compound has become commercially available. In situ derivatization also can be used to recover this epoxy alcohol from the epoxidation reaction. Progress in the isolation of 2-methyloxiranemethano is reflected in entries 1-3 of Table 3, and... 

Oxirane compounds such as 3,4-epoxy-l-butene [49], (2,3-epoxy-l-propanol) glycidol [50], and 2,3-epoxybutanoic acid [51] can be used to... 

---