“…Krause reaffirmed the problem of comparing two very similar classes (cisoid and transoid SPAnPS) with each other, where the differences are present between the two structure motifs, but the generalisability of explanations cannot be founded on these two points alone. This drawback was partly tackled by Stern (2006Stern ( , 2009 with the synthesis of the asymmetric compounds Ph 2 (S− −)P−An−H (SPAnH) and Ph 2 (S− −)P−An−Me (SPAnMe).…”