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.
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.
β-(2-Oxocyclopentyl)ethylaryl ketones are transformed under acid conditions via a 2-aryl-bicyclo[3.2.1]oct-2-en-8-one intermediate into a mixture of arylcycloheptene carboxylic acids. The scope and the mechanism of the reaction are both discussed.
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.