No abstract

Several γ,δ-unsaturated β-diketones were prepared by acylation of the lithium enolates of cyclic ketones by cinnamoyl chlorides. Reaction of the cinnamoylcyclohexanones with 2 equivalents of hydrazoic acid in sulfuric acid gave bicyclic lactams in good yields. The mechanism of this process involves a Schmidt reaction, followed by addition of HN 3 to the enone, migration of the aryl group onto nitrogen, and a cyclisation in which the arylamino group is displaced by the amide nitrogen. The scope of the reaction is limited to the preparation of 7-5 bicyclic systems from enoyl cyclohexanones, other precursors gave dihydropyrones or complex mixtures.

Cells exist in an astonishing range of volumes across and within species. However, our understanding of cell size control remains limited, due in large part to the challenges associated with accurate determination of cell volume. Much of our comprehension of size regulation derives from yeast models, but even for these morphologically stereotypical cells, assessment of cell volume has mostly relied on proxies and extrapolations from two-dimensional measurements. Recently, the fluorescence exclusion method (FXm) was developed to evaluate the size of mammalian cells, but whether it could be applied to smaller cells remained unknown. Using specifically designed microfluidic chips and an improved data analysis pipeline, we show here that FXm reliably detects subtle differences in the volume of fission yeast cells, even for those with altered shapes. Moreover, it allows for the monitoring of dynamic volume changes at the single-cell level with high time resolution. Collectively, our work highlights how the coupling of FXm with yeast genetics will bring new insights into the complex biology of cell growth.