Cycloadditions of thiocarbonyl ylides withN-sulfinylamines

Thiofenchone s‐methylide and its spiro‐1,3,4‐thiadiazoline precursor

“…The hydroborations of bornene and apobornene proceed exclusively from the endo side. When the same procedure was applied to 2,7,7-trimethylnorbornene (27), it was concluded that the major product must be that of endo-hydroboration: 23/24 ‫ס‬ 13:87 was found [19]. The connection with our 13 C NMR parameters stems from the near identical ratios of 23/24 observed in catalytic hydrogenation, 27:73 for Pt/H 2 [19], and 29:71 for Pd/H 2 (this work).…”

“…Anal. calcd for C 27 Thioxanthione (37). Compounds 6 (420 mg, 2.00 mmol) and 37 (502 mg, 2.20 mmol) in 6 mL of THF at 40ЊC were stirred for 8 hours (49 mL of N 2 , 98%).…”

“…Adamantanethione (3) afforded thiadiazolines of types 1 and 2 in a ratio of 9:91 in pentane, and 90:10 was observed in methanol, both at ‫03מ‬ЊC [3,4].…”

“…

3,4)-thiadiazoline] (6), prepared from thiofenchone and diazomethane, extrudes N 2 (t 1/2 22 min, 46ЊC, toluene) and furnishes the S-methylide 7 which, in turn, closes the thiirane ring or else is intercepted by 1,3-cycloadditions to dipolarophiles (tetracyanoethylene, maleic anhydride, N-methyl-1,2,4-triazoline-3,5-dione, aromatic thioketones). When thiocarbonyl S-methylide 7 is set free in methanol, fenchone S,O-dimethylacetal is formed as an HX adduct.

…”