The key intermediate (9) for the totalsynthesis of antitumor sesquiterpene vernolepin (1) was prepared in seventeen steps from 2,5-dihydroanisyl alcohol. Intramolecular Michael addition (7→ 8) afforded the cis-2-oxadecalone system, which was stereospecifically converted to 9 by using the enolization character of 8.
Non-Cryogenic, Ammonia-Free Reduction of Aryl Compounds
申请人:University of Pittsburgh - Of the Commonwealth System of Higher Education
公开号:US20220089508A1
公开(公告)日:2022-03-24
A method of reducing an aromatic ring or a cyclic, allylic ether in a compound includes preparing a reaction mixture including a compound including an aromatic moiety or a cyclic, allylic ether moiety, an alkali metal, and either ethylenediamine, diethylenetriamine, triethylenetetramine, or a combination thereof, in an ether solvent; and reacting the reaction mixture at from −20° C. to 30° C. for a time sufficient to reduce a double bond in the aromatic moiety to a single bond or to reduce the cyclic, allylic ether moiety.
New compounds 4-methyl-1,4-cyclohexadiene-1-carboxaldehyde syn-oxime, 4-methoxymethyl-1,4-cyclohexadiene-1-carboxaldehyde syn-oxime, and 4-(1-methoxyethyl)-1,4-cyclohexadiene-1-carboxaldehyde syn-oxime, as well as the compound 1,4-cyclohexadiene-1-carboxaldehyde syn-oxime, are found to have a high degree of sweetness which is accompanied by very little off-taste. The compounds have good stability even in acid solution. They give no evidence of toxicity and can be employed in foods and beverages as synthetic sweetening ingredients.
Enantioselective Total Synthesis of the Antifungal Natural Products Chlorotetaine, Bacilysin, and Anticapsin and of Related Compounds: Revision of the Relative Configuration
作者:Hanno Wild
DOI:10.1021/jo00089a019
日期:1994.5
Enantioselective and diastereoselective syntheses of the title antifungal natural products and some of their diastereoisomers are described. Key steps include the diastereoselective 1,6-addition of bislactim ether 14 and a stereoselective, deprotonation of ketone 17 using lithium (S,S)-bis(1-phenylethyl)amide as a chiral base. All natural products possess the (S)-configuration at C-1 of the substituted cyclohex(en)yl residues of the C-terminal amino acids, which contradicts the assignments in the literature. At physiological pH most of the dipeptides are instable and react by an intramolecular 1,4-addition with the formation of 6-oxoperhydroindoles.