Activation of Marginally Reactive Boron Enolates by MeLi for the Formation of Enol Phosphates and Synthesis of the Δ(9)-THC Intermediate.
The addition of MeLi to boron enolates produced by the 1,4-addition of Ar2Cu(CN)Li2 to BF3·OEt2-activated enones was followed by the reaction with ClP(O)(OEt)2 to afford the corresponding enol phosphates in moderate to good yields. The scope of this method was examined with sterically hindered or electronically biased enones and/or reagents. This activation of boron enolates was successfully applied to the synthesis of the methyl ether of Δ(9)-tetrahydrocannabinol.
Department of Bioengineering, Tokyo Institute of Technology , Box B-52, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan.
Hiroki
H
Kawada
Department of Bioengineering, Tokyo Institute of Technology , Box B-52, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan.
Atsushi
A
Ikoma
Department of Bioengineering, Tokyo Institute of Technology , Box B-52, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan.
Narihito
N
Ogawa
Department of Bioengineering, Tokyo Institute of Technology , Box B-52, Nagatsuta-cho 4259, Midori-ku, Yokohama 226-8501, Japan.
Yuichi
Y
Kobayashi
D001895:Boron / Q000737:chemistry*; D013759:Dronabinol / Q000138:chemical synthesis* / Q000737:chemistry; D007202:Indicators and Reagents / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D008738:Methyl Ethers / Q000138:chemical synthesis* / Q000737:chemistry; D009943:Organophosphorus Compounds / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*
D007202:Indicators and Reagents; D008738:Methyl Ethers; D009943:Organophosphorus Compounds; D010710:Phosphates; D013759:Dronabinol; D008094:Lithium; D001895:Boron