The sterically crowded 2,2,4,4-tetramethyl-3-thioxocyclo-as the α-chlorosulfenyl chlorides 8 and 12 which yielded corresponding disulfides after treatment with equimolar butanone (7) and its dithio analogue 9 were found to react readily with gaseous chlorine to afford 1:1 and 1:2 adducts, amounts of thioacetic acid. respectively. The stable, crystalline products were identified
Recently, the number of reports dealing with various as-chlorine can stop at the CT complex stage 2, at the stage of the salt 3, or go all the way to the α-chlorosulfenyl chloride pects of thioketone chemistry increased remarkably and conversions such as cycloadditions, reductions, and oxi-4. [2] In some cases overchlorination of 4, resulting in the formation of the corresponding gem-dichloro compound 5 dations involving CϭS double bonds have been in the focus of attention of many research groups [1] . However, reports of (observed with thiobenzophenone [3] , dithiocarboxylates [4] ,
and trithiocarbonates [5] ) could not be avoided. Traces of reactions with halogens (fluorine, chlorine, bromine) which would be expected to result in formation of synthetically water can hydrolyse adducts 2 and/or 3 to the corresponding carbonyl compounds 6. [6] [7] The course of chlorine ad-useful α-halosulfenyl halides have been very scarce.
dition to the CϭS double bond in 1 is expected to involve intermediates of type 2 and/or 3 and can be followed in solution by means of IR or 13 C NMR, even in cases where only labile adducts are formed such as during the attempted reaction of Cl 2 with 4,4-dichloro-1,3-dithietane-2-thione [8] .
There have been described some specifically substituted thiocarbonyl compounds 1, other than thioketones, which react smoothly with chlorine to give stable adducts of type 4, i.e. thiophosgene [29] , halothioformates [7Ϫ11] , halodithioformates [5,9Ϫ18] , trithiocarbonates and their derivatives. [5,12,19Ϫ24] Alkyl and aryl groups R 1 and/or R 2 (typically present in common thioketones) are expected to stabilize the intermediates 2 and/or 3, and thus counteract the formation of the final adduct 4. However, one has to take into account that the same effects which counteract the formation of stable 4 may favour the hydrolysis of 2 and/or 3 as well as Scheme 1. Possible interactions between thiocarbonyl compounds and chlorine phenone [6] . A report mentioning the formation of the labile Lodz, 3-chloro-2,2,4,4-tetramethyl-3-pentanesulfenyl chloride PL-90Ϫ136 Lodz, Poland from di(tert-butyl) thioketone (R 1 ϭ R 2 ϭ tBu in 1) is lack-