Activation episulphides

The ruthenium(II) - ethylene episulphide complex [152] may serve as a model for the coordination of tiiranes at the catalyst active site. 

Other changes of OA structure, such as the addition of a methyl group on its G-ring, as in DTX-1, or the substitution of the double bond in the B-ring at the 9-10 carbon position with an episulphide (acanthifolicin), do not appreciably modify the activity. ... 

The sesquiterpenes caryophyllene and humulene react with elemental sulphur under mild conditions to produce the episulphides (87), (88), and (89) [52]. The level of these compounds is higher in oil prepared by steam distillation at 100°C than in oil obtained by vacuum distillation at 25 C. Thus, higher levels of these compounds are likely to be introduced into beer by late addition of hops to the copper than by dry hopping. Myrcene reacts with sulphur less readily, but with a suitable activator a mixture of at least 10 products is obtained of which (90) is the major constituent present in hop oil. 

Biologically Active Steroidal Episulphides.—Y. Muraoka, I. Yahara, F. Itoh, H. Watanabe, and N. Nara, Oyo Yakuri, 1978, 16, 739 Chem. Abstr., 1979.90, 146 142)... 

Thionyl chloride reacts with compounds containing active methylene groups to yield olefins (445). With deoxybenzoin the episulphide (446) is the product. ... 

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