The absolute configuration of 6,8-dioxabicyclo[3.2.1]octane and several methyl substituted derivatives
作者:N. Ibrahim、T. Eggimann、E.A. Dixon、H. Wieser
DOI:10.1016/s0040-4020(01)81959-1
日期:1990.1
enantiomers of 6,8-dioxabicyclo[3.2.1]octane and the alkyl substituted derivatives, exo- and endo-7-methyl, exo- and endo-5,7-dimethyl, 7,7-dimethyl, and exo- and endo-7-ethyl-5-methyl (exo- and endo-brevicomin), were synthesized stereoselectively with known configuration by standard synthetic methods, or with baker's yeast, or both. The correlation between the absoluteconfiguration of the bicyclic rings and
Et2MeN×HI-Catalyzed Reaction of Arylboronic Acids with 2-Acyl-2,3-dihydro-4H-pyrans Leading to 2-Aryltetrahydrocyclopenta[1,3,2]dioxaboroles
作者:Takahide Fukuyama、Takahiro Okamura、Ilhyong Ryu
DOI:10.1055/s-0030-1260007
日期:2011.5
The reaction of arylboronic acids with 2-acyl-2,3-dihydro-4H-pyrans proceeded smoothly in the presence of a catalytic amount of Et2MeNËHI to give acyl-substituted 2-aryltetrahydrocyclopenta[1,3,2]dioxaboroles in good yields. The reaction is likely to involve the acid-catalyzed ring-opening reaction of pyrans, an intramolecular aldol reaction, and condensation with boronic acids.
Stereoselective synthesis of either (±)-exo- or (±)-endo-brevicomin via hydride reduction of a 2-acylpyranyl intermediate
作者:David P. Richardson、Whitney Wilson、Rebecca J. Mattson、Dawn M. Powers
DOI:10.1039/p19900002857
日期:——
Reduction of the ethyl ketone (5) with L-Selectride or zinc borohydride proceeds stereoselectively to give the alcohols syn-(6) or anti-(7), respectively, which are converted, in turn, into (±)-exo-brevicomin and (±)-endo-brevicomin.