Oxidation of 3, 3'-Methyrenebis(guaiazulene) with Peracetic Acid in Hexane

Abstract

Oxidation of 3, 3'-methyienebis (guaiazulene)[1A₁] with peraceticacid in hexane at 25°C for 1h gave one major product : Namely, oxidation product of the nucleus, 5-isopropyl-3, 8-dimethyl-1- [(3-guaiazulenyl)methyl] -4(3aH)-azulenone [1B] (40.0% isolated yield). As minor products (0.5-7.5% isolated yield), twelve kinds of compounds were separated : benzofulvene [1A₂], 3, 3'-biguaiazulene [1A₃], 3-formylguaiazulene [1H], azulenylbenzofulvenes ([1A₄], [1A₅]), isomer of [1B] ([1D]), azulenylinclenols ([1F₁], [1F₂], [1G₁]), oxidationp roduct of [1B] ([G₂]), and other oxidation products with skeltal rearrangements ([1C1], [1C₂]) ; struuctures of these products were established on the basis of the spectroscopic (UV, MS, IR, and NMR) data. Possible reaction pathways are suggested for the formation of the thirteen kinds of products.