Reactions of Thioketones with Dichlorocarbene

✍ Scribed by Grzegorz Mlostoń; Jaroslaw Romański; Anna Swia¸tek; Heinz Heimgartner

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: German
• Weight: 159 KB
• Volume: 82
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/(sici)1522-2675(19990609)82:6<946::aid-hlca946>3.0.co;2-p

✦ Synopsis

Âczyk on the occasion of his 60th birthday

The reactions of sterically crowded cycloalkanethiones of type 2 with CHCl 3 /NaOH under phase-transfer catalysis (PTC) with benzyl(triethyl)ammonium chloride (TEBA) as catalyst afforded the corresponding gem.dichlorothiiranes of type 3 in good yields (cf. Scheme 2 and Table ). The desulfurization, which, in some cases, occurred spontaneously, led to (dichloromethylidene)cycloalkanes of type 4. Similar results were obtained using Seyferths reagent in boiling benzene. In the case of 2,2,6,6-tetramethylcyclohexanethione, reaction under PTC conditions after 3 h yielded only the corresponding dichloromethylidene derivative; on the other hand, workup after 1 h gave (2,2,6,6-tetramethylcyclohexylidene)methanethione (thioketene 9; Scheme 5).

By the above-described procedure, 2,2-dichloro-3,3-diphenylthiirane (3a, cf.

[8] [10]) was obtained in 80% yield as a stable crystalline material 5 ). Similarly, the spirocycloaliphatic derivatives 3b ± e were stable and could be stored at room