A facile synthesis of benzo(b)furan derivatives including naturally occurring neolignans via regioselective lithiation of ortho-cresols using the bis(dimethylamino)phosphoryl group as a directing group.
A facile synthesis of 2-arylbenzo[b]furans via directed lithiation of ortho-tolyl tetramethylphosphorodiamidates as the key step is described. Lithiation of ortho-tolyl tetramethylphosphorodiamidates at -105°C followed by reaction with aromatic esters and then acidic treatment led to 2-arylbenzo[b]furans in modest overall yields. The utility of this strategy has been demonstrated in regioselective and short syntheses of the naturally occurring neolignans carinatin, eupomatenoid-1, and eupomatenoid-13.
Synthesis of (±)-licarin B and eupomatenoids-1 and -12: A general approach to 2-aryl-7-alkoxy-benzofuranoid neolignans
作者:Thomas A Engler、Wenying Chai
DOI:10.1016/0040-4039(96)01619-x
日期:1996.9
New syntheses of the title compounds are described using Lewis acid-promoted reactions of styrenes with N-phenylsulfonyl-1,4-benzoquinone monoimines to regioselectively form the 2-arylbenzofuranoid ring system followed by conversion of the aromatic N-phenylsulfonyl moiety into a propenyl substituent. Copyright (C) 1996 Elsevier Science Ltd
WATANABE, MITSUAKI;DATE, MUTSUHIRO;KAWANISHI, KENJI;HORI, TAKAKO;FURUKAWA+, CHEM. AND PHARM. BULL., 39,(1991) N, C. 41-48