General Description
Methyl trimethylsilylacetate on reaction with lithium diisopropylamide in THF at -78°C yields methyl lithiotrimethylsilylacetate. It also undergoes Peterson olefination to yield mainly
Z-isomers of steroid 17β-side chain methyl acrylates.
Purification Methods
Methyl trimethylsilylacetate [2916-76-9] M 146.3, b 65-68o/50mm, d 4 0.89. Dissolve it in Et2O, shaken with 1M HCl, wash with H2O, aqueous saturated NaHCO3, H2O again, and dry it (a precipitate may be formed in the NaHCO3 solution and should be drawn off and discarded). The solvent is distilled off, and the residue is fractionated through a good column. IR (CHCl3) max 1728cm1 . [Fessenden & Fessenden J Org Chem 32 3535 1967, Matsuda et al. J Org Chem 45 237 1980, Beilstein 4 III 1855, 4 IV 3974 for Et ester.]
