The preparation of 13-methylgon-4-enes and novel 13-polycarbonalkylgon-4-enes by a new total synthesis is described. 13-Alkylgon-4-enes having progestational, anabolic and androgenic activities are prepared by forming a tetracylic gonane structure unsaturated in the 1,3,5(10),9(11) and 14-positions, selectively reducing in the B- and C-rings, and converting the aromatic A-ring compounds so-produced to gon-4-enes by Birch reduction and hydrolysis.
Allenic amino acids. 1. Synthesis of .gamma.-allenic GABA by a novel aza-Cope rearrangement
作者:Arlindo L. Castelhano、Allen Krantz
DOI:10.1021/ja00318a076
日期:1984.3
Synthese de l'acide amino-4 heptadiene-5,6oique (inhibiteur de la GABA transaminase) a partir de la condensation du succinimide avec le pentyne-4 ol-2
Synthese de l'acideamino-4 heptadiene-5,6oique (inhibiteur de la GABA transaminase) a partir de la condensed du succinimide avec le pentyne-4 ol-2
Thia-acyliminium cyclisations
作者:J.A.M. Hamersma、P.M.M. Nossin、W.N. Speckamp
DOI:10.1016/s0040-4020(01)96567-6
日期:1985.1
by the intermediacy of N-acyliminium species. A similar process applied to lactams 21b–25b affords the pyrrolizidine type compounds 26–35 through consecutive azonium-Cope rearrangement and N-acyliminium ringclosure. Additional results are concerned with the use of aromatic rings as π-nucleophiles.
Toward the first totalsynthesis of 16-membered macrolide antibiotic hygrolidin, the C1C17 seco-acid fragment and the C18C25 masked hemiacetal subunit as potential precursors have been synthesized in enantiomerically homogeneous forms.
The Synthesis and the Electronic Spectra of 1, 1′-Dianthrylpoly-ynes
作者:Shuzo Akiyama、Masazumi Nakagawa
DOI:10.1246/bcsj.40.340
日期:1967.2
The synthesis of 1, 1′-dianthryldi- and tetra-acetylenes has been reported previously by the present authors. Now, 1, 1′-dianthryltri-, penta- and hexa-acetylenes have been synthesized in order to complete the series of 1, 1′-dianthrylpoly-ynes. It is well known that the square of the wavelength of the longest absorption maxima, λmax in the electronicspectra of some series of poly-enes and poly-ynes