Intramolecular Diels–Alder reactions using chiral ruthenium Lewis acids and application in the total synthesis of ent-ledol
作者:Sirinporn Thamapipol、E. Peter Kündig
DOI:10.1039/c1ob06121f
日期:——
ligand BIPHOP-F and a Cp or an indenyl ‘roof’ can efficiently catalyze asymmetric intramolecular Diels–Alder reactions of trienes to form bicyclic adducts with good to excellent asymmetric induction. This reaction forms the key step in a totalsynthesis of ent-ledol in 96% ee. The synthesis also helps to clarify the stereochemical assignment of ledol and inconsistencies in the measured optical rotation