Intramolecular Ene and Related Reactions, Part 9. Photochemically Induced Synthesis of Allylsilane Carbaldehydes
作者:Lutz F. Tietze、Josef R. Wünsch
DOI:10.1055/s-1990-27070
日期:——
Allylsilane carbaldehydes are valuable substrates for the tandem Knoevenagel allylsilane and iminium cyclization. They can easily be prepared by a photochemical α-cleavage of cyclic ketones bearing a trimethylsilylmethyl group in the α-position (Norrish Type I cleavage). The photolytic process is facilitated by the silicon due to its stabilization of a radical in the β-position. Irradiation of the ketones 15a-d leads mainly to the aldehydes 16a-d. In addition irradiation of 19a gives mostly the aldehyde 20.
烯丙基硅烷羰基醛是串联 Knoevenagel 烯丙基硅烷和亚胺环化反应的重要底物。烯丙基硅烷羰基醛是串联 Knoevenagel 烯丙基硅烷和亚胺环化反应的重要底物,可以通过对δ位带有三甲基硅甲基的环酮进行光化学δ-裂解(Norrish I 型裂解)而轻松制备。硅能稳定 δ 位上的自由基,从而促进了光解过程。辐照酮 15a-d 主要生成醛 16a-d。此外,辐照 19a 主要得到醛 20。