Juzo Nakayama

Synthesis and Properties of S-Aminothiiranium Salts of anti- and syn-9,9’-Bibenzonorbornenylidenes and 2,2’-Biadamantylidene

S-Aminothiiranium salts 5a-c of anti- and syn-9,9-bibenzo-norbornenylidenes and 2,2-biadamantylidene were synthesized by reacting thiiranes 3a-c with O-mesitylenesulfonylhydroxylamine. Decomposition of 5a and 5c in CD 2 Cl 2 at rt yielded a mixture of the corresponding alkenes and thiiranes, whereas that of 5b yielded 1,2-thiazetidin-2-ium salts 8b. A CH 2 Cl 2 solution of 8b was treated briefly with aq. NaHCO 3 at 0 °C to produce N-unsubstituted 1,2-thiazetidinelOb.

Pummerer reaction of 4,7-di-tert-butyl-3h,8h-1,2,5,6-dithiadiazocine 1-oxide; formation of 1,4-dithiins

The Pummerer reaction of 4,7-di-tert-butyl-3H,8H-1,2,5,6-dithiadiazocine 1-oxide (4a) with (CF3CO)2O in the presence of DBU has produced 2,5-di-tert-butyl-1,4-dithiin (5a) in 67% yield, whereas the reaction of 4a with (CF3CO)2O alone gave a 5:2 mixture of 5a and 2,6-di-tert-butyl-1,4-dithiin (5a′) in 61% yield.