α,α-Diacetyl Cyclic Ketene Dithioacetals: Odorless and Efficient Dithiol Equivalents in Thioacetalization Reactions - Yu, Haifeng; Liu, Qun; Yin, Yanbing; Fang, Qunxin; Zhang, Jingping; Dong, Dewen (Synlett, 2004)