Synthetic applications of di-tert-butoxyethyne, II: New syntheses of squaric, semisquaric and croconic acids
作者:Anna Bou、Miquel A. Pericàs、Fèlix Serratosa
DOI:10.1016/s0040-4039(00)86831-8
日期:1982.1
New synthetic entries to: a) the semisquaric acid skeleton of the natural mycotoxin “moniliformin”; b) the squaric acid system, and c) the croconic acid system, via (η-tetra-tert-butoxycyclopentadienone)(η-cyclopentadienyl)cobalt, starting from di-tertbutoxyethyne are reported.
Synthesis of croconic and hydrocroconic acids from di-t-butoxyethyne. Electrochemical demetallation of a cyclopentadienyl organocobalt complex
作者:Anna Bou、Miquel A. Pericàs、Fèlix Serratosa、Josep Claret、Joan Miquel Feliu、Carlos Muller
DOI:10.1039/c39820001305
日期:——
The electrochemicaldemetallation of (η-tetra-t-butoxycyclopentadienone)(ηcyclopentadieny)cobalt, readily available fromdi-t-butoxyethyne leads to tetra-t-butoxyclopentadienone which can be converted into hydrocroconicacid by trifluoroacetic acid hydrolysis and then croconicacid by oxidation in basic medium.
Insights into the Molecular Structure and Reactivity of α,ω-Dialkoxy-Substituted Ethyne and Butadiyne
作者:Rolf Gleiter、Daniel B. Werz、Frank Rominger、Evgeny Zhutov、Nikolay S. Zefirov、Marina V. Proskurnina
DOI:10.1002/ejoc.200700617
日期:2007.12
photoelectron spectrum of bis(tert-butoxy)butadiyne (4a) are reported. Bis(tert-butoxy)ethyne (3a) and 4a were treated with highly electrophilic [η2-bis(tert-butylsulfonyl)ethyne](carbonyl)(η5-cyclopentadienyl)cobalt (10). In both cases a CpCo-stabilized cyclobutadiene ring resulted substituted by two tert-butylsulfonyl groups and either two tert-butoxy groups (11) or one tert-butoxy group and one tert-butoxyethynyl
The reactivity of the bis-oxygen substituted alkyne bis(tert-butoxy)acetylene (3) towards titanocene- and zirconocene complexes of btmsa [btmsa = bis(trimethylsilyl)acetylene] was investigated. Those metallocenes with unsubstituted Cp ligands (Cp = η5-cyclopentadienyl) afforded metallacyclopropenes by alkyne replacement, but only in low yields. The metallocenes bearing the sterically more demanding