The full paper from the Jacobsen group on the HKR of epoxides has appeared and makes excellent reading (Schaus S E et al, J Am Chem Soc, 2002, 124, 1307). Of course, this is a process which has been scaled up since the first reports of 1997 (Science 1997, 277, 936) and 1998 (J Org Chem, 1998, 63, 6776). For liquid epoxides, the reaction is run neat or very concentrated, so the exotherm of >30 kcal/mol is important for scale up, particularly for low MW epoxides. Controlled addition of the ring opening nucleophile (e.g. water) is therefore crucial to the scaleability of the process.

The paper also discusses catalyst recycling and the effectiveness is shown below. The paper explores the wide variety of terminal epoxides which can be resolved using the HKR methodology.