Use of the oxazole-olefin diels-alder reaction in the total synthesis of the monoterpene alkaloids (-)-plectrodorine and (+)-oxerine.
A full account of the total synthesis of two monoterpene alkaloids, (-)-plectrodorine [(-)-1] and (+)-oxerine [(+)-3], is presented. The key steps involved are the formation of the oxazole alcohol 10 from the gamma-butyrolactone 9 and the intramolecular Diels-Alder reaction of the oxazole-olefins 13a, b. Since the sign of specific rotation for the synthetic (+)-3 was different from that reported for natural oxerine, the absolute configuration of this alkaloid is not yet fully understood.
Ohba
Masashi
M
Advanced Science Research Center, Kanazawa University, Kakuma-machi, Japan. ohba@p.kanazawa-u.ac.jp
Izuta
Rie
R
Shimizu
Emi
E
D000475:Alkenes / Q000737:chemistry*; D004121:Dimethyl Sulfoxide; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008968:Molecular Conformation; D039821:Monoterpenes / Q000138:chemical synthesis*; D010080:Oxazoles / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
D000475:Alkenes; D007202:Indicators and Reagents; D039821:Monoterpenes; D010080:Oxazoles; C508579:oxerine; C508577:plectrodorine; D004121:Dimethyl Sulfoxide