An ethanol extract of Lactarius necator gave 3,8-oxa-13-hydroxy-lactar
-6-en-5-oic acid gamma-lactone and furanether A, besides other known s
esquiterpenes. Syntheses of these internal ethers, as well as the 13-o
xa-lactonic analogue, were performed. The antifeedant properties of th
e internal ethers measured against the storage pests Tribolium confusu
m, Trogoderma granarium and Sitophylus granarius are reported.