Preparation of DL-2,3,4-trihydroxybutylarsonic acid and dl-2,3-dihydroxybutane-1,4-bis(arsonic acid): starting compounds for novel arsonolipids.

The reaction of DL-1,3-butadiene diepoxide and of DL-1,4-dibromo-2,3-butanediol with aqueous alkaline sodium arsenite, "Na(3)AsO(3)", gave mixtures of the title arsonic acids which can be separated by anion exchange resin. Characterization of by-products leads to a better understanding of these reactions. These compounds are valuable intermediates for the preparation of novel arsonic acids and bis(arsonic acids).

The reaction of allyl and benzylarsonic acids with thiols: mechanistic aspects and implications for dioxygen activation by trivalent arsenic compounds.

The reaction of allyl and benzylarsonic acids with thiophenol gives not only the expected diphenyl alkyldithioarsonites and diphenyl disulfide but also various other compounds arising from the decomposition at the arsenic(V) oxidation level (the arsonic acids) by thiophenol and at the arsenic(III) oxidation level (mainly the alkyldithioarsonites) by thiophenol and by dissolved dioxygen. The reaction of these arsonic acids with 4-nitrothiophenol, which is not oxidized by dioxygen, revealed that the arsenic(III) of these alkyldithioarsonites is the active atom towards dioxygen. However, the reaction of allyl, benzyl, and 2-picolylarsonic acids with DL-penicillamine gives the expected products with no or very small oxidative decomposition. The decomposition pathways of allyl and benzylarsonic acids were elucidated. The results are briefly discussed in the contexts of the use of arsonic acids in chemotherapy and the ability of arsenic(III) compounds to generate reactive oxygen species.