Cleavage of 1,3-Dithianes via Acid-Catalyzed Hydrolysis of the Corresponding 1,3-Dithianemonooxides

Abstract

The hydrolysis of 1,3-dithianes to their parent carbonyl compounds via their corresponding monosulfoxides was systematically investigated. The oxidation of the 1,3-dithianes was carried out in high yields using tert-butyl hydroperoxide. Acid-catalyzed hydrolysis of the monosulfoxides to the carbonyl compounds was then performed in excellent yields. The cleavage reactions were monitored by gas chromatography and kinetics were investigated on substrates varying in electron density and steric requirements. Neither effect prevented high overall yields in the cleavage reaction.

Total Synthesis of Silyl‐Protected Early Intermediates of Polyketide Biosynthesis

“…The synthesis of the model mononaphthol‐ketide 29 / 30 thus represents an 8‐deoxybisdithioketal‐protected form of our synthetic goal and so the essential framework of the first target analogue molecule 2b had been achieved. Unfortunately, though, and to our frustration, the protecting groups could not be removed without destruction of the molecule, notwithstanding the use of a large variety of different cleaving reagents,42–44 and so this approach, although successful for the construction of the carbon skeleton of 2b , had to be abandoned at this stage to allow us to pursue alternative routes.…”

2-(Trimethylsilyl)-1,3-dithiane 1-Oxide as a Convenient Reagent for the Transformation of Aldehydes and Ketones into Homologous Carboxylic Acids

“…10 Oxidation is not required for the addition reaction of the dithiane with carbonyl compounds, but it is needed to facilitate the subsequent cleavage of the dithioacetals to give carboxylic compounds. 8 In addition, the required elimination step to give the intermediate ketene acetal (see Scheme 1) is facilitated when a modified Peterson olefination procedure is used.…”

Studies on the double alkylation of 2,2-disubstituted-1,3-dithiacycloalkane-S-oxides: synthesis of tertiary thiol derivatives

“…Further deprotonation and methylation then gave a 73% yield of the dimethylated sulfoxide 13 which, pleasingly, 40 could be converted in high yield (84%), to the dimethyl 1,2-dithiolane 14 by treatment with acid. Reaction with hydrochloric acid in acetonitrile at room temperature 10 was found to give the best results; hydrochloric acid in methanol 13 gave lower yields, while HCl in ether 14 or toluene returned only the starting sulfoxide.…”

“…It was not possible to effect a second alkylation with methyllithium as base and methyl iodide as alkylating agent, 24b 10 being recovered unchanged in 69% yield, and no evidence for the formation of 25 was obtained. This may have been due to the axial methylene group of the menthyl auxillary group blocking approach of the electrophile.…”