Hydrogen bonding control in the oxidative cyclisation of 1,5-dienes

The regioselective dihydroxylation of a series of functionalised polyenes is described. Under acidic conditions, the osmate ester derivatives obtained from oxidation with OsO4/TMEDA undergo an intramolecular cyclisation reaction forming functionalised tetrahydrofurans with high stereoselectivity and in good yield. The generality of this method is illustrated with an application to the synthesis of a bis-tetrahydrofuran ring system. (C) 2001 Elsevier Science Ltd. All rights reserved.