The reaction of functionalised mono or dichlorinated materials 1a–6a with an excess of lithium and a catalytic amount of a naphthalene supportedpolymer (P-152, easily prepared by radical copolymerisation of 2-vinylnaphthalene, styrene and divinylbenzene) in THF either in the presence (Barbier-type conditions) or not of different electrophiles [Me3SiCl, BunCHO, BuiCHO, PhCHO, Et2CO, c(C3H5)2CO, Pri2CO
Naphthalene-catalysed lithiation of 3-chloro-2-chloromethyl-propene: A barbier-type practical alternative to the trimethylenemethane dianion
作者:Diego J. Ramón、Miguel Yus
DOI:10.1016/0040-4039(92)88181-4
日期:1992.4
The reaction of equimolar amounts of 3-chloro-2-chloromethylpropene (2) and a carbonyl compound (3) with an excess of lithium powder and a catalytic amount (6%) of naphthalene in tetrahydrofuran at −78°C leads, after hydrolysis with water, to the corresponding diols 4 in a Barbier-type process.
The reaction of functionalised mono or dichlorinated materials 1a–6a with an excess of lithium and a catalytic amount of a naphthalene (PN) or biphenyl (PB) supportedpolymer (eassily prepared by radical copolymerisation of 2-vinylnaphthalene or 4-vinylbiphenyl with vinylbenzene and divinylbenzene) in THF either in the presence or not of different electrophiles [Me3SiCl, iPrCHO, PhCHO, Et2CO, (CH2)4CO
Naphthalene-catalysed lithiation of 3-chloro-2-chloromethylpropene in a Barbier-type process with carbonyl compounds
作者:Cecilia Gómez、Diego J. Ramón、Miguel Yus
DOI:10.1016/s0040-4020(01)89923-3
日期:1993.5
The reaction of 3-chloro-2-chloromethylpropene (1) and carbonyl compounds (2) with an excess of lithium powder in the presence of a catalytic amount of naphthalene (6%) in tetrahydrofuran at -78 to 20-degrees-C leads, after hydrolysis, to the corresponding methylenic 1,5-diols 3 in a Barbier-type process. The treatment of the crude diols 3 with 12 M hydrochloric acid affords selectively the corresponding substituted dihydropyrans 6.