β-Trichlorostannyl Ketones and Aldehydes. Preparation and Facile Amine-Induced Dehydrostannation Leading to α-Methylene Ketones and Aldehydes

Article abstract of DOI:10.1021/jo00027a008

Ring-opening reactions of siloxycyclopropanes 1 with SnCl4 take place under mild reaction conditions and site-selectively to give β-trichlorostannyl ketones and aldehydes 3 in high yields.The β-trichlorostannyl ketones and aldehydes thus obtained readily undergo base-induced dehydrotrichlorostannation at room temperature to give the corresponding α-methylene ketones and aldehydes 4.The reactions are quite general for amines, such as pyridine, triethylamine, N,N,N',N',-tetramethylethylenediamine (TMEDA), and 1,4-diazabicyclo<2.2.2>octane (DABCO), and the yields are good to high.One-pot conversion from siloxycyclopropanes 1 to α-methylene ketones or aldehydes 4 by consecutive treatment of 1 with SnCl4 and TMEDA is also successful.The 1H NMR, 13C NMR, 119Sn NMR, and IR spectral properties of β-stannyl ketones and aldehydes are also reported.