Carbonsäuresynthesen mit 1.1‐Dichlor‐äthylen, III. Die Einführung der Essigsäuregruppe in das Adamantansystem

Abstract

Die aus Brom-adamantanen, Adamantolen oder Adamantyl-acetaten in Schwefelsiiure gebildeten Adamantyl-( 1 )-Kationen reagieren mit 1. I -Dichlor-Bthylen in hohen Ausbeuten zu den entsprechenden Adamantan-essigsauren-( I ). Ebenso lassen sich 1 -Brom-adamantanessigsiiuren-(3) und I .3-Diacetoxy-adamantane in Adamantan-diessigsBuren-( 1.3) uberfhhren. Alkalisalze der I-Broni-adamantan-essigsauren-(3) hydrolysieren schon bei Raumteniperatur mit Halbwertszeiten von 10--20 Minuten zu I -tlydroxy-adamantan-essigsiiure1~-(3).Die Umsetzungen von tertiaren Alkoholen, deren Estern oder Isoolefinen n i t 1.1-Dichlor-athylen in Schwefelsaure erniiiglicht es, tert.-Alkylessigsauren im ,,Eintopfverfahren" darzustellen 2'. Als kennzeichnend fur alle bisher beschriebenen Synthesen dieser Art hat sich erwiesen, daB mit wachsenden Alkyl-oder Cycloalkylresten in den tertiaren Alkoholen die Carbons~ure-AusDeuten stark abfallen. Das aus dem bicyclischen rvnns-DecaloL(9) resultierende Carboniumion ist schlieBlich nicht mehr befahigt, unter Anlagerung an 1.1 -Dichlor-athylen in Decalyl- (9) Tm Vergleich zu den anderen Beispielen verlauft die Synthese der 3.5.7-Trimethyladamantan-essigsaure-( 1 ) (4d) weniger glatt, weil etwa 15 --17 ",: des CarboniumionenBildners durch den freigesetzten Chlorwasserstoff in das reaktionstrage 1-Chlor-3.5.7-trimethyl-adamantan umgewandelt werden.

Synthesis and Anion Binding Assessment of Novel Adamantane Amidopyrroles

“…The strategy for synthesis of 1 and 2 was to prepare the corresponding building blocks, aminoadamantanes and the pyrrole carboxylic acid, followed by amide bond formation between the prepared fragments (Scheme 1). Aminoadamantane derivatives 3 and 4 were obtained from 1,3-adamantanedicarboxylic [32] and 1,3-adamantanediacetic acid, [33] respectively via the corresponding adamantyl cyanides. [34] Synthesis of pyrrole precursors 5 and 6 is known and very well described in the literature (see Supporting information for more details).…”

Reactions of adamantanes in electrophilic media

“…124,125 (3-Bromo-1-adamantyl)acetic acid is formed in 95% yield on treating (1-adamantyl)acetic acid with bromine at 20 8C for 18 h followed by refluxing the reaction mixture for 6 h. (3-Bromo-5methyl-1-adamantyl)-and (3-bromo-5,7-dimethyl-1-adamantyl)acetic acids were obtained under the same conditions. 126 Adamantane-2-carboxylic acid is brominated with Br 2 in the presence of AlBr 3 to give 5,7-dibromoadamantane-2-carboxylic acid. 127 1,3-Bis(trifluoromethyl)adamantane ( 74) reacts with anhydrous hydrogen fluoride in the presence of SF 4 yielding 1,3bis(trifluoromethyl)-5,7-difluoroadamantane (75).…”

“…Using this approach, 3-methyl-, 3,5-dimethyl-and 3,5,7trimethyl-adamantane-1-carboxylic acids have been synthesised in 72%, 49.8% and 38.5% yields, respectively. 111 Also, the synthesis of 3-methyl-, 106 3-methyl-5-ethyl-and 3-bromomethyladamantane-1-carboxylic acids 107 as well as of 3-carboxymethyl-1-adamantyl-, 3-carboxymethyl-5-methyl-1-adamantyl-and 3-carboxymethyl-5,7-dimethyl-1-adamantyl-acetic acids 126 has been described. Adamantane-2-carboxylic acid was synthesised from 2-hydroxyadamantane (6).…”

Synthesis, antiherpes, and antibacterial activity of N-linked conjugates of eremomycin with adamantanecarboxylic acids

“…Acylation of eremomycin I in dioxane:water (1:1) at pH 9 by a small excess of the acid chlorides of 1-adamantylacetic (IIa) or p-(1-adamantyl)phenoxyacetic (IIb) acids produced in good yields adamantyl-containing amides IIIa and -b that were monoacylated at the NHMe group (Scheme 1). Starting 1-adamantylacetic acid (IIa) was prepared by a modified Bott reaction [15] through the reaction of 1-adamantanol with 1,1-dichloroethylene in a mixture of trifluoroacetic (TFA) and sulfuric (96%) acids. Heating Electrospray ionization mass spectrometry (ESI-MS) of N 1 -substituted eremomycins IIIa and -b turned out to be an effective physicochemical method for determining the structures of the products (Fig.…”