Dithia-isotwistanes

CoUin s-oxidation of the 10 -isotwistanol 275 (3.2.3.) yielded ketone 344, which on LiAlH4-reduction gave exclusively the 10 -isotwistanol 328 (87%), the starting material for the reaction with thionylchloride (- 325 3.4.3.) . 

An interesting result was obtained in the oxidation of275 with one equivalent of hydrogen peroxide. Although the main product (60%) was the S(2) -sulfoxide  

345 (attack from the most unhindered side) still 19% of the S(7) -oxide 347 was isolated, whereas analogous oxidation of the corresponding acetate 262 yieldiecj almost exclusively the S(2) -sulfoxide 346.  

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For the preparation of 2,7-dithia-isotwistanes the mercaptane 196 as well as the disulfide 197 were used as starting materials. Treatment of 196 with bromine or... 

Dithia-isotwistan-lO-one 344) actually represent a combination of the two P-keto-sulfides 336 and 341. Its UV-spectrum indeed reflects this situation quite well exhibiting four absorption maxima. 

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