... Ro 31-6930 VIA CLAISEN REARRANGEMENT AND TANDEM REGIOCONTROLLED CYCLISATION Michael R Attwood, Ian Churcher, Rachel M Dunsdon, David N Hurst and PhIlIp S Jones' Roche Products LImited, Welwyn Garden Cdy, Herts AL7 3AY ... Experrmental runs for 5 hours at 165oC !n 1,2-d/chlorobenzene Analysis of products by HPLC St02 25x0 46 cm column 3O%v/v ethyl acetate / hexane UV detectton 254 nM ...