Addition of functionalized organolithium reagents to p-benzoquinones and cyclohexadienones: synthesis of functionalized cyclohexadienones, dienols and dienediols
作者:Alfred Fischer、George Narayanan Henderson
DOI:10.1016/s0040-4039(00)81347-7
日期:1983.1
Low temperature addition of functionalized alkyllithium reagents to p-benzoquinones produces 4-alkyl-4-hydroxycyclohexa-2,5-dienones, and reaction of excess of the reagents with quinones yields 1,4-dialkylcyclohexa-2,5-diene-1,4-diols. With 4-acetoxy-, 4-hydroxy-, and 4-methoxy-4-methylcyclohexa-2,5-dienones the corresponding dienols are obtained. A one-step synthesis of the antibiotics 4-acetamido-
Ring Opening of Cyclic Vinylogous Acyl Triflates Using Stabilized Carbanion Nucleophiles: Claisen Condensation Linked to Carbon−Carbon Bond Cleavage
作者:David M. Jones、Marilda P. Lisboa、Shin Kamijo、Gregory B. Dudley
DOI:10.1021/jo100249g
日期:2010.5.21
Addition of stabilized carbanionic nucleophiles to cyclic vinylogous acyl triflates (VATs) triggers a ring-opening fragmentation to give acyclic β-keto ester and related products, much like those observed traditionally in the Claisen condensation. Unlike in the classical Claisen condensation, however, the VAT-Claisen reaction described herein is rendered irreversible by C−C bond cleavage, not by deprotonation
A new and versatile route for the synthesis of highly substituted benzenoids
作者:Jeffrey A. Robl
DOI:10.1016/s0040-4039(00)97412-4
日期:1990.1
A newroute for the synthesis of highly substituted benzenoids has been developed. Key steps include the conversion of unsaturated lactone 7 to carboxy substituted cyclohexenone 8 followed aromatization to give phenol 9. The phenolic functionality provides a handle for further modification to give substituted benzenoids of type 2.
(Emblica officinalis) medicinal plant, is a potent and selective inhibitor of aldose reductase (AKR1B1). Synthesis of a C‐analogue wherein the –CH2– unit replaces the glucosyl‐O remains unexplored. Synthesis of C‐analogue 4 in particular and its aldose reductase inhibition (ARI) activity studies have been performed.
Hapalosin, a new MDR reversing agent, and its congener 8-deoxyhapalosin have been synthesized via macrolactamization. A new procedure for selective N-methylation of a vicinal amino alcohol is uncovered in the course of this study.