Novel ring expansion of cyclopentanones to seven membered rings
作者:Masakazu Tanaka、Hiroshi Suemune、Kiyoshi Sakai
DOI:10.1016/s0040-4039(00)82030-4
日期:1988.1
By treatment with BF3/ethyleneglycol, cyclopentanones with the carbonyl function at the C3-position of α-side chain undergo the ring cleavage to build up the seven membered rings, and this novel ringexpansion was applied to the synthesis of bulnesol.
Dityltin bis(triflate) is a mild Lewisacid which catalyzes clean Michael addition of enol silylethers. The new catalyst allows to employ various labile acceptors such as methyl vinyl ketone and 2-cyclopentenone which do not undergo smooth reaction with conventional Lewisacids. A variety of enol silylethers are also employable and thus 2-(trimethylsiloxy)propene, the simplest one in this class of
Surface-mediated solid phase reaction. Mukaiyama-Michael addition of silyl enol ethers to methyl vinyl ketone on the surface of alumina
作者:Brindaban C. Ranu、Manika Saha、Sanjay Bhar
DOI:10.1016/s0040-4039(00)91983-x
日期:1993.3
Clean and efficient Michael addition of silyl enol ethers to methyl vinyl ketone has been achieved through a simple solvent-free reaction on the surfac
Indium-trichloride catalyzed Michael reaction of silyl enol ethers with α,β-unsaturated carbonyl compounds under neat condition
作者:Teck-Peng Loh、Lin-Li Wei
DOI:10.1016/s0040-4020(98)00394-9
日期:1998.6
In the presence of a catalytic amount of indium (III) trichloride (InCl3) (20 mol%), ketene silyl enol ethers react quickly with α,β-unsaturated ketones and esters to afford the corresponding Michael adducts in moderate to good yields. Indium(III) trichloride can be recovered and reused without decrease in yields.
Regioselective hydration of alkynones by palladium catalysis
作者:Katsuharu Imi、Kumiko Imai、Kiitiro Utimoto
DOI:10.1016/s0040-4039(00)96302-0
日期:1987.1
Diketones are regioselectively prepared from alkynyl ketones under mild conditions by palladium catalysis; 5-heptyn-2-one and 2-(2-nonynyl)cyclohexanone give 1,4-dikektones whereas 2-(2-heptynyl)cyclopentanone and 5,6-didehydroprostaglandin E2 methyl ester afford 1,5-diketones.