Flexible synthetic approach to a (S)-norcamphor-based hydroperoxide:: An efficient oxidant for asymmetric sulfoxidations

The renewable tertiary (S)-norcamphor-based hydroperoxide 3 has been efficiently obtained by a simple 4-step route. Remarkably, complete diastereocontrol was observed in the hydroperoxidation step. This oxidant, when used in the Ti-catalyzed asymmetric sulfoxidation, showed to be as reactive as previously reported hydroperoxide 2, but more importantly, high chemoselectivity and improved asymmetric induction were achieved. The synthetic approach used offers the opportunity for designing a variety of functionalized and potentially more efficient norcamphor-based hydroperoxides. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006).