Reactions of hydroxyquinones with dimethyl sulfoxide-acetic anhydride

A Ring‐Distortion Strategy from Marine Natural Product Ilimaquinone Leads to Quorum Sensing Modulators

“…As we will discuss below, this compound presents enhanced reactivity relative to 1 . Treatment of 15 with dimethyl sulfoxide (DMSO) and acetic anhydride produced stable π‐delocalised sulfur‐ylide 3 in 50 % yield , . Reduction of this ylide by zinc powder in acetic anhydride (catalytic amount of trimethylamine) resulted in the formation of thio‐substituted aromatic compound 5 .…”

Sulfonium ylides derived from 2-hydroxy-benzoquinones: crystal and molecular structure and their one-step conversion into Mannich bases by amine N-oxides

“…Crystals for X-ray diffraction were obtained by slow evaporation of a concentrated aqueous solution,. 1 Mannich bisbetaine 6. Bisylide 3 (0.52 g, 2 mmol) was suspended in DMF (50 mL) and heated to 70 8C.…”

“…The precipitate was isolated by filtration, washed thoroughly with ethyl acetate and dried in vacuo to give 6a (0.49 g, 72%), mp 265 8C (decomp.). 1 …”

The effect on fungal growth of some 2,5-dihydroxy-1,4-benzoquinones

“…Thus this interesting compound is now readily available. Cain (7) has reported the synthesis of many alkyldiphenyl-dihydroxybenzoquinones, during his investigations of their antileukemic properties, but routes to such compounds bearing other functional groups as substituents of the phenyl moieties have been hampered by the sensitivity of the dihydroxybenzoquinone system to oxidation (17). It has now been shown that the diacetate of 4,4'-dimethoxypolyporic acid can be nitrated in about 90% yield to the dinitro derivative (V, R = OMe, R' = OAc, R" = NO,) using cupric nitrate in acetic anhydride, and the nitro group reduced to amino without degradation of the quinone ring.…”