抄録
Condensation products of oleic acid and paraformaldehyde in acetic acid solution were saponified and then fractionated by recrystallization, and the following two substances were obtained [1 part of oleic acid reacted with 2 parts of formaldehyde effectively in 1 hr when 1% of HClO4 was used as a catalyst (Fig. 3)].
One of them had mp 117-118°C and seemed to have pyranol-4 structure because of its characteristics (Table 1 & Fig.-1) and it was considered as 3-octyl-4-hydroxy-5-carboxyhexyltetrahydropyran (or 3-heptyl-4-hydroxy-5-carboxyheptyltetrapyran). Pigulevskii assumed in his report about the same reaction that the product had pyranol-3 structure.
And the other was C18H36O3, mp 70-71°C, A.V. 184.5, and from the IR spectrum (shown in Fig.-2), it was considered as monohydroxystearic acid (mixture of 9-and 10-hydroxy acids).
As the catalyzers, perchloric acid was most effective, and sulfuric acid and borontrifluoride etherate were also fairly effective (Table 3).
