Racemic aziridine-2-carbonitrile (ruc-1) in MeCN solution reacts regioselectively (> 90%) with 2 equiv. of TsOH at room temperature to form the hydrotosylate of racemic 03- tosylserinenitrile (ruc-2) via a B-ring opening (Scheme 2). A similar regioselective reaction takes place between rac-1 and H3P04 to produce racemic 03-phosphoserinenitrile (rac-3) which is in turn a source of glycolaldehyde phosphate (= formylmethyl ...