1,3-Dithiolan-2-ones have been obtained by reaction of 1,3-dithiolane-2-thiones and epoxides in the presence of HBF4·Et2O. The reactions, carried out in anhydrous CH2CL2 at 0–5 °C→room temperature (Procedure A) or in anhydrous chlorobenzene at 0–5-→80 °C (Procedure B), gave product yields of 63–95%. By Procedure B it was also possible to isolate the intermediates 1-oxa-4,6,9-trithiaspiro[4.4]nonanes in good yields (66–85%). Reaction pathways are proposed.
1,3-二
硫杂
环戊烷-2-酮可通过1,3-二
硫杂环
戊烷-2-硫酮与
环氧化物在
HBF4·Et2O存在下反应得到。在无
水CH2Cl2中于0–5 °C至室温进行反应(方法A)或在无
水氯苯中于0–5 °C至80 °C进行反应(方法B),产物收率可达63–95%。通过方法B还可高收率(66–85%)分离出中间体1-氧杂-4,6,9-三
硫杂螺[4.4]
壬烷。提出了反应途径。