A rapid divergent synthesis of highly substituted delta-lactones.
[reaction: see text] Nucleophilic 1,2-addition of (Z)-gamma-silyloxyvinylzinc reagents to ethyl glyoxylate followed by desilylation and cyclization affords 3,6-dihydro-3-hydroxypyran-2-ones in good chemical yields. In situ formation of allylic phosphates followed by reaction with RCu(CN)Li reagents affords substituted 5,6-dihydropyran-2-ones. The parent compound, 3,6-dihydro-3-hydroxypyran-2-one, undergoes allylic phosphate formation, cuprate-mediated allylic substitution, and 1,4-conjugate addition to afford trans-4,5-disubstituted tetrahydropyran-2-ones in a one-pot process.
Dieter
R Karl
RK
Howard L. Hunter Laboratory, Department of Chemistry, Clemson University, Clemson, South Carolina 29634-0973, USA. dieterr@clemson.edu
Guo
Fenghai
F
D002384:Catalysis; D003500:Cyclization; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry; D011753:Pyrones / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D007783:Lactones; D009942:Organometallic Compounds; D011753:Pyrones