Complementary diastereoselective reduction of cyclic gamma-keto acids: efficient access to trisubsituted gamma-lactones.
Complementary reduction conditions have been identified that provide ready access to each respective diastereomer of bi- and tricyclic, trisustituted gamma-lactones starting from the corresponding cyclic gamma-keto acids. Subjection of cyclic gamma-keto acids to silane reagents in the presence of trifluoroacetic acid provides all syn-gamma-lactones, while reduction with trialkylborohydrides furnishes the syn,anti-gamma-lactones. The conditions are mild and provide the product lactones in good yields and modest to excellent selectivity.
Bercot
Eric A
EA
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523.
Kindrachuk
David E
DE
Rovis
Tomislav
T
D007651:Keto Acids / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry*; D010084:Oxidation-Reduction; D013237:Stereoisomerism
D007651:Keto Acids; D007783:Lactones