“…The orientation was determined by linking up the various reactions by compounds such as the amino-and halogeno-tropolones formed by more than one method and then checking the orientation of these key compounds by alkaline ring-contraction to benzenoid derivatives. Of the various electrophilic substitutions, nitration, halogenation,3bd 45,59 sulphonation, 60 and hydroxymethylation G1 all cause reaction at the a-and the y-position, as had been predicted from theoretical consideration^.^^ Nitrosation 6i 6 2 and diazo-coup1ingJz4-369 G3 however, are difficult to effect in any position other than y and consequently the presence of a bulky group in the P-position, e.g., the isopropyl group of hinokitiol, may affect both the ease of these reactions and the properties of the product, as in the unusual rearrangement of the azo-compounds derived from hinokitiol to the so-called hinopurpurins 64 brought about by crystallisation from ethanol :…”