Photochemically induced domino

Another photochemically induced domino process consisting of three steps was employed for the formation of 1,2-disubstituted cyclopentanes 5-39, as described by Tietze and coworkers. Irradiation of a mixture of 5-36, dimethyl malonate and catalytic amounts of the Lewis acid Me2AlCl in a Pyrex flask caused a Norish Type I cleavage of 5-36, followed by an intramolecular hydrogen shift to give the acyclic... 

The same group has developed another synthetically useful photochemically induced domino transformation. Irradiation of the enaminecarbaldehydes 5-40a or 5-40b in the presence of acrylic acid ester 5-41a or acrylonitrile 5-41b afforded the quinolizidines 5-45a and 5-45b as well as the pyrido[l,2-a]azepines 5-45c and 5-45d, respectively, with high stereoselectivity [14]. Only very small amounts of the corresponding diastereomers 5-46a-d were detected. 

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