Biochemical Studies on “Bakanae” Fungus. Part 55 Synthesis of Gibberellins

Part II. Infrared Spectra of the Lactones of Cyclohexane Series

Abstract

In order to clarify the structure of ring A of gibberellins, thirteen lactones of cyclohexane series, of which eight were new, were prepared to examine their infrared spectra. So far as the experiment is concerned, γ-lactones show the characteristic absorption band in the range 1775-1782cm^-1 in dioxane, while σ-ones in the range 1730-1762cm^-1. Since the absorption band due to lactone carbonyl of gibberellins occurs at the range 1777-1786cm^-1 in dioxane, the lactone ring of gibberellins seems to be γ.