Furyl -1,3-dithiane

Many dithioacctals, useful for synthetic purposes, are now commercially available, including bis(phenylthio)methane (1), dithiane itself and a number of 2-substituted dithianes (2), but also more exotic ones such as (3). (In contrast to the stench of (1), compound (3) is non-odoriferous ) 

When using dithioacetals as intermediates the most tedious step is often their hydrolysis to carbonyl compounds. As a consequence, many methods have been developed to realize that conversion and, in their review [43], Grobel and Seebach give experimental details for most of the procedures known at that time. In view of the fundamental importance of dethioacetalization, we now describe some promising new methods that have appeared since. 

Laszlo introduced an oxidative cleavage of dithioacetals by their clayfen (4) and claycop reagents under inild conditions with excellent yields [46, 47]. These reagents are convenient sources of the nitrosonium ion NO+, a soft reactive Lewis acid species, well adapted for attack of the soft sulfur atom. 

The reagent was prepared by dissolution of iron(llt) nitrate nonahydrate in acetone (the proportions are 45 g of Fe(N03)39H20 in 750ml of acetone for 60 g of K-10 clay). This resulted in a clear, rust-coloured solution which rapidly decayed to a muddy, light-brown suspension, to which the 

Claycop was prepared in a similar manner [47] and, unlike clayfen, showed no loss of reactivity on standing in an open box. 

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