Silicon in Synthesis. 10. The (Trimethylisilyl)allyl Anion: A β-Acyl Equivalent for the Conversion of Aldehydes and Ketones into γ-Lactones

Article abstract of DOI:10.1021/ja00535a600

The (trimethylsilyl)allyl anion reacts with a number of ketones and aldehydes to give adducts 11-21, resulting from the γ mode of ambident reactivity.These adducts were epoxidized to provide the corresponding α,β-epoxysilanes 23-31.Treatment of the epoxysilanes with methanol in the presence of boron trifluoride etherate gave the lactol methyl ethers 32-39.Jones oxidation of the lactol methyl ethers gave γ lactones 40-45.Addition of bromine to the 4-hydroxy vinylsilane derivative 19 gave oxetane 47 which was converted into the compounds 49, 50, and 51.Application of the (trimethylsilyl)allyl anion, as its zinc counterion, to the synthesis of 17-spirosteroidal lactones is described.