Mellor,J.M.; Webb,C.F., Journal of the Chemical Society. Perkin transactions II, 1974, p. 17 - 22
作者:Mellor,J.M.、Webb,C.F.
DOI:——
日期:——
Efficient and highly stereoselective syntheses of enantiomerically enriched C(1)-C(7) subunits of erythronolides
作者:Mohammed Ahmar、Isabelle Romain、Robert Bloch
DOI:10.1021/jo00063a009
日期:1993.5
Stereocontrolled efficient syntheses of the C(1)-C(7) fragments of deoxyerythronolide and erythronolide seco acids are described. The key step of these syntheses involves a highly stereoselective aldol condensation between an enantiomerically enriched 2-arylpropanal and the lithium enolate of the racemic 2-methyl-5-norbornenyl ethyl ketone, which establishes in one operation the relative and absolute configurations of the three stereocenters C(2), C(3), and C(4). After syn-selective reductions of the carbonyl group, the configuration required at carbon C(6) was introduced by highly selective reactions carried out on the double bond regenerated by a thermal cycloreversion.
Endo-2-methyl-bicyclo[2.2.1]-hept-5enyl ethyl ketone: an useful and highly stereoselective synthon for aldol reactions
An excellent aldehyde diastereofacial selectivity has been observed during the aldol condensation between the lithium enolate of endo-2-methyl-bicyclo[2.2.1]-hept-5-enyl ethyl ketone 1 and a variety of alpha-methyl chiral aldehydes. 2-Aryl- and 2-vinyl-propionaldehyde gave rise to the predicted syn, syn "Felkin-Anh" diastereoisomers. In contrast beta-alkoxy or beta-silyloxy alpha-methyl aldehydes lead to the syn, anti aldols arising from an apparent chelation control.
BLOCH R.; GILBERT L., TETRAHEDRON LETT., 27,(1986) N 30, 3511-3514
作者:BLOCH R.、 GILBERT L.
DOI:——
日期:——
BLOCH, R.;GILBERT, L., TETRAHEDRON, 44,(1988) N 9, 2523-2539