An Efficient Synthesis of Epoxydiynes and a Key Fragment of Neocarzinostatin Chromophore
摘要:
A key structural feature of the Neocarzinostatin chromophore is a reactive epoxydiyne. We present here a new method for the preparation of epoxydiynes by the addition of an allenyl zinc bromide to a propargylic ketone.
New Approaches to Bicylic Vinyl Heterocycles from Propargylic Acetals
作者:Frédéric Le Strat、David C. Harrowven、Jacques Maddaluno
DOI:10.1021/jo048794d
日期:2005.1.1
2-vinylbenzofurans and 3-vinylfuropyridines. Attempts to extend the cascade to [4.4.0] binuclear heterocycles met with limited success. An alternative, two-step entry to such ring systems has been developed using the palladium-induced cyclization/hydride capture methodology. A new route to isoquinilinones from simple benzamides is also disclosed.
Synthetic strategies to epoxydiynes and a key synthon of the neocarzinostatin chromophore
作者:Olivier Thominet、James R. Baker、Hugh Britton、Zac C. Etheridge、Marco G. Soscia、Stephen Caddick
DOI:10.1039/b711196g
日期:——
towards the synthesis of epoxydiynes which represent an unusual structural feature of the neocarzinostatinchromophore. A number of different routes to these epoxydiynes have been explored with varying success. Ultimately a concise and convergent approach was developed, which involved the addition of an allenyl zinc bromide to propargylic ketones/aldehydes followed by epoxide formation. This new protocol
Acetals of 4-amino-2-butynal : Application to the synthesis of N6-substituted adenines with an acetylenic side chain, potential cytokinins
作者:M. Haidoune、M. Giffard、R. Mornet、A. Gorgues
DOI:10.1016/s0040-4039(00)99296-7
日期:1989.1
Acetylenedicarbaldehyde monoacetals 4 are good precursors for the synthesis of the 4-amino-1,1-dialkoxy-2-butynes 6, through simple reactions. Coupling of these amines 6 with 6-chloropurine leads to the N6-substituted adenines 1, potential cytokinins.
New Carbanionic Access to 3-Vinylindoles and 3-Vinylbenzofurans
作者:Frédéric Le Strat、Jacques Maddaluno
DOI:10.1021/ol026351v
日期:2002.8.1
[GRAPHICS]A simple route to 3-vinylbenzofurans, 3-vinyifuropyridines, and 3-vinylindoles from readily accessible acetylenic precursors is described. A standard halogen-lithium exchange triggers an irreversible! addition on the triple bond, according to a 5-exo-dig heterocyclization process, followed by a lithium ethoxide elimination. A final isomerization of the exocyclic allene provides a 1,3-dienic system that can react with acrylates, in thermal or hyperbaric conditions, to provide the expected [4+2] cycloadducts.