Enantioselective halolactonisation of bis-γ,δ-unsaturated carboxylic acid derivatives: use of a sultam and oxazolidine-2-ones as chiral auxiliary
摘要:
Iodolactonisation of heptadienoic acid derivatives 2 and 3 having oxazolidin-2-ones or a sultam as chiral auxiliary gave the chiral iodolactones 4 and 5 in moderate to excellent enantiselectivity.
Diastereotopic olefins were differentiated in iodolactonization with concomitant face differentiation using (2R,5R)-bis(methoxymethyl)pyrrolidine as a chiral auxiliary to afford chiral lactones in enantioselective manner.