Thioaldehydes containing virtually any -substitutent can be generated by photofragmentation of phenacyl sulfides. Donor-substituted derivatives are reactive toward electron-rich dienes and give 2 + 4 cycloadducts with regiochemistry corresponding to advanced C-C bonding in the transition state. Acceptor-substituted thioaldehydes react in the opposite regiochemical sense with C-S bonding advanced. A number of unusual thioaldehydes have been trapped, including the parent HCH=S, Me3SiCHS, Ph2P(0)CH=S, PhS02CH=S, and CNCH=S, as well as more conventional alkylor acyl-substituted derivatives.

Two routes for the synthesis of cis-N-protected-3-methylamino-4-methylpiperidine (3) were examined:  a route hinging on the electrochemical oxidation of carbamate 1 to install a ketone at the 3 position of the piperidine followed by reductive amination (disconnection A), and a route involving the hydrogenation of an appropriately functionalized pyridine (disconnection B). While both routes to the desired compound were ultimately successful, the pyridine hydrogenation approach proved to be more amenable to kilogram-scale preparations due to the crystallinity and purity of intermediates in that route.

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