Bart Kesteleyn

Synthesis of Two Naphthoquinone Antibiotics, Dehydroherbarin and 6-Deoxybostrycoidin

The synthesis of two naphthoquinone antibiotics, dehydroherbarin (7) and 6-deoxybostrycoidin (5), was accomplished by reaction of 3-acetonyl-2-bromomethyl-6,8-dimethoxy-1,4-naphthoquinone (23) with either triethylamine or ammonia, respectively. This is the first report on their synthesis.

Synthesis of 1,3-disubstituted naphtho[2,3-c]pyran-5,10-diones

Abstract Two convenient and simple methods for the synthesis of 1,3-disubstituted naphtho[2,3- c ]pyran-5,10-diones, which involve the introduction of acylmethyl groups onto 2-(1-hydroxyethyl)-1,4-naphthoquinones and subsequent base- and acid-induced ring closure, were developed.

SYNTHESIS OF 3-ALKENYLAMINES, 4-ALKENYLAMINES AND 3-ALLENYLAMINES VIA A TRANSAMINATION PROCEDURE

Abstract 3-Alkenylamines, 4-alkenylamines and 3-allenylamines were synthesized conveniently by potassium t-butoxide induced transamination of α-vinylaldimines, α-allylaldimines or α-allenylaldimines followed by hydrolysis with aqueous oxalic acid.

Synthesis of 2-alkoxymethyl-3-trifluoromethyl-1,4-naphthoquinones

Abstract 2-Alkoxymethyl-3-trifluoromethyl-1,4-naphthoquinones were conveniently synthesized in two steps by treatment of 2-substituted-3-bromo-1,4-dimethoxynaphthalene with CF3COONa/CuI and subsequent dealkylative oxidation by treatment with cerium(IV) ammonium nitrate.

Synthesis of 3-alkyl- and 3-aryl-2-aza-anthraquinones

Abstract Reaction of 2-acylated 3-phenoxymethyl-1,4-naphthoquinones with aqueous ammonium hydroxide, provides a facile entry to 3-alkyl- and 3-aryl-benz[g]isoquinoline-5,10-diones.

Synthesis of 1H-2-naphtho[2,3-c]thiapyran-5,10-dione-2,2-dioxide, a 2-sulfone analogue of pentalongin

Abstract The synthesis of 1H-2-naphtho[2,3-c]thiapyran-5,10-dione-2,2-dioxide (2), a 2-sulfone derivative of the natural pyranonaphthoquinone pentalongin (1), was accomplished using the acid-catalysed cyclisation of the naphthoquinone sulfone acetal 6 as a key step in the synthesis.

Synthesis of 3-chloroanthranilates from α,γ,γ-trichloro-β-iminoesters

Abstract 3-Chloroanthranilates have been prepared by a short pathway involving dehydrohalogenation of α,γ,γ-trichloro-β-iminoesters, which were obtained by trihalogenation of the corresponding enaminoesters. This route opens the way to a number of previously unknown functionalised anthranilates, which are potential starting materials for a variety of heterocyclic and biologically interesting compounds.

A NEW SYNTHESIS OF ALKYL 1-ALKYL-2-METHYLPYRROLE-3-CARBOXYLATES BY RING TRANSFORMATION OF 2-CHLORO-2-ACETIMIDOYLBUTYROLACTONES

Abstract Reaction of 2-chloro-2-acetimidoylbutyrolactones with sodium methoxide or sodium ethoxide in the corresponding alcohol provides a facile one-step synthesis of methyl or ethyl 1-alkyl-2-methylpyrrole-3-carboxylates from readily available starting materials.