| 摘要 |
PROBLEM TO BE SOLVED: To achieve a novel, practical and efficient stereoselective asymmetric synthesis of a four-ring coumarin compound, which is expected for its physiological activity and for its use in drug discovery, and to achieve an efficient synthesis of calophyllum coumarin. SOLUTION: A hydroxyketone compound represented by formula (I) [wherein, R1 is H or a hydrocarbon group which may have a substituent; R2 and R3 are each identically or independently a hydrocarbon group which may have a substituent; R4 is H or a hydrocarbon group and R5 is a hydrocarbon group, or R4 and R5 form a carbocycle which may have a hydrocarbon group or a substituent.] or a hydroxyketone compound having an activated hydroxy group undergoes, in the presence of optically active cinchona alkaloid, an intramolecular oxo-Michael reaction in a solvent having high permittivity to form a cis- or trans-form of a compound represented by formula (II) [wherein, R1, R2, R3, R4 and R5 are the same as before mentioned.] or a chromanone ring compounds thereof. The obtained compounds are then reduced.
|
