The sodium acetate-buffered peracetic acid oxidation of various 1-methoxybicyclo[2.2.2]oct-5-enones (4a-f), and (14), prepared by hydrolysis of the adducts (3) [(13)] derived from dihydroanisole derivatives (2) [(12)] and 2-chloroacrylonitrile leads to 4-substituted cyclohex-2-en-1-one 4-acetic acid derivatives (7) [(15)].
Stepwise Acid-Promoted Double-Michael Process: An Alternative to Diels−Alder Cycloadditions for Hindered Silyloxydiene−Dienophile Pairs
作者:Michael E. Jung、David G. Ho
DOI:10.1021/ol062980j
日期:2007.1.1
The hindered diene 1 reacts with 3-methylcyclohexenone 6 catalyzed by triflimide to produce the Mukaiyama Michael product 7 (low-temperature quenching) or the [4+2] cycloadduct 8 (quenching at 0 degrees C). Reaction of the hindered diene 23 with 2-methylcyclohexenone 12 with 5:1 AlBr3:AlMe3 afforded a 71% yield of a 1.9:1 mixture of two cycloadducts. Hydrolysis of the major isomer gave the dione 27', a model for the BCD ring system of pentacyclic triterpenes.
HOLMES, ANDREW B.;MADGE, NIGEL C., TETRAHEDRON, 45,(1989) N, C. 789-802
作者:HOLMES, ANDREW B.、MADGE, NIGEL C.
DOI:——
日期:——
MAGDE N. C.; HOLMES A. B., J. CHEM. SOC. CHEM. COMMUN., 1980, NO 20, 956-957