From 1,2-Dithiolans Type C

Synthesis.—From 1,2-Dithiolans (Type C). The general synthesis of isothiazoles from 1,2-dithiolans (see Organic Compounds of Sulphur, Selenium, and Tellurium, volumes 2, 3, 4, and 5 ) continues to be exploited. The 1,2-dithiolyIium-4-olates (1) are cleaved by ammonia and subsequently cyclize to give isothiazol-4-ols (2 X = OH). Methylation in HCIO4 gives (3), which are convertible into (4) by base.  

From P-Aminocrotonates Type C). A one-step synthesis of glycosylamino-isothiazoles (5) involves the reaction between a glycosyl isothiocyanate (RNCS) and MeC(NH2)=CHC02Et.  

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From 1,2-Dithiolans (Type C).—Several variations of the general synthesis of isothiazoles from 1,2-dithiolans (see these Reports, Vol. 2, p. 563) have been employed in the production of further series of isothiazole deriv-atives. In a comparative study, this route has been described as the most generally applicable method of preparing di- and tri-alkylisothiazoles. ... 

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