| Abstract: | ![]()
Acetylenes that possess two bulky alkyl substituents reacted with sulfur dichloride to furnish the corresponding 2,3‐dialkyl‐2,3‐dichlorothiiranes ( 5 ) nearly quantitatively. The alkaline hydrolysis of 5 afforded 2,3‐dialkylthiirene 1‐oxides ( 10 ) in high yields. These two reactions could be successively carried out in one flask, and 2,3‐di‐tert‐butyl‐, 2,3‐di‐(1‐adamantyl)‐, and 2‐(1‐adamantyl)‐3‐tert‐butylthiirene 1‐oxides ( 10a–c ) were obtained in 70, 80, and 90% yields, respectively, based on the starting acetylenes, thus providing the most convenient synthesis of thiirene 1‐oxides. Disulfur dichloride also reacted with acetylenes to give 5 in good yields with the elimination of one sulfur atom. Although the alkaline hydrolysis of 5 provided 10 exclusively, acid hydrolysis gave a mixture of α‐oxothioketone 9 and thiirene 1‐oxide 10 in modest yields. All thiirene 1‐oxides 10a–c isomerized to produce α‐oxothioketones 9 in high yields when heated in boiling toluene. Reactions of a bis‐acetylene ( 18 ) with disulfur dichloride and with sulfur dichloride gave a dihydropentathiepin ( 19 ) in high yields. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:424–430, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10070 |
