The synthesis and some rearrangements of 2-acetyl-4,6-diethyl-1,3,4-trihydroxycyclo-2,6-dien-5-one

Abstract

Ring contraction of a synthetic analogue of humulone gives cis- and trans-compounds analogous to isohumulone A and isohumulone B under a wide variety of conditions. Since these isomers fail to undergo interconversion under a wide variety of conditions, they must therefore be formed independently. A new type of rearrangement has also been noted which results in the formation of 5-ethyl-3,4-dihydroxy-3-propionylcyclopentan-1-one; this is formed by a pathway which apparently involves neither isohumulone-type nor humulinic acid-type structures as intermediates.