Stereoselective rhodium-catalyzed conjugate addition of boronic acids to unprotected delta-hydroxy-gamma-butenolides. Synthesis of (-)-7-oxamuricatacin and beta-substituted derivatives.
The chiral delta-hydroxy-gamma-butanolide moiety is widely found among biologically active natural products. We report herein the stereoselective synthesis of beta-substituted analogues of these compounds by the Rh(I)-catalyzed conjugate addition of boronic acids to chiral delta-hydroxy-gamma-butenolides, easily prepared from the chiral pool. The reaction takes place with high trans diastereoselectivity without protection of the hydroxyl group. The three-step syntheses of (-)-7-oxamuricatacin (R1 = H, R2 = CH2-O-(n)C10H21) and of new beta-substituted 7-oxamuricatacin analogues (R1 = aryl, vinyl) is reported.
Navarro
Cristina
C
Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, 28040-Madrid, Spain.
Moreno
Ana
A
Csákÿ
Aurelio G
AG
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000737:chemistry; D001897:Boronic Acids / Q000737:chemistry*; D002384:Catalysis; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism
C534901:7-oxamuricatacin; D001897:Boronic Acids; D005663:Furans; C004511:butenolide; D012238:Rhodium; D015107:4-Butyrolactone