338 Proceedings of the Royal Irish Academy. 



several days. The oily solid which had separated, together with a further 

 quantity of this solid obtained by evaporating the solution, was dissolved in 

 hot alcohol, from which it separated as colourless crystals melting at 158°C., 

 identical with those mentioned above. 



3. Equimoleeular amounts of di-p-methoxyphenyl-methyltetrahydro- 

 pyrone and anisaldehyde were dissolved in cold alcoholic hydrochloric acid, 

 and the solution was let stand in a stoppered flask for a few days. The 

 solution turned dark-red with separation of oily crystals. After recrystalli- 

 sation from hot alcohol tliis substance melted at 158°C., and proved to be 

 identical with that obtained in the last experiment. It gave on analj'sis 

 the following results : — 



0'1126 substance gave 0-3237 CO, and 0-0630 H,0, 

 corresponding to C 78-4, H 6-2. 

 C.sHasO, requires C 78-8, H 6-1. 



This substance crystallises in colourless, rectangular prisms, which are 

 sparingly soluble in hot alcohol and readily soluble in chloroform. Con- 

 centrated sulphuric acid dissolves the crystals forming an orange-coloured 

 solution. 



The formation of the substance from di-^j-methoxyphenyl-metbyltetra- 

 hydropyrone can be represented by the following equation : — 



C2„H,304 + (CHsOjCeH,. CHO = C^.H^eO, + 2H,0. 



4. In an experiment similar to one described above (B 2), 6 g. of piperonal 

 and 2-4 g. of anisylidene-methylethyl-ketone in 20 c.c. of ice-cold alcoholic 

 hydrochloric acid was allowed to stand for a few days. The solid, which 

 had separated, was then filtered and washed repeatedly with warm alcohol. 

 When recrystallised from a mixture of chloroform and alcohol it melted at 

 195°C., and gave on analysis the following results : — 



0-1871 substance gave 0-5055 CO, and 0-0827 H,0, 

 corresponding to C 73'7, H 5-0. 

 C38H,.,06 requires C 74-0, H 4-8. 



The compound consists of light yellow, platy crystals, which are sparingly 

 soluble in hot alcohol, and readily soluble in chloroform. The crystals are 

 coloured reddish-purple on contact with strong sulphuric acid, in which they 

 dissolve, forming a dark-red solution. This substance is evidently analogous 

 to the compound CosUseOi obtained from anisaldehyde and anisylidene- 

 methylethyl-ketone. 



