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Bis(pentamethylcyclopentadienyl)methanol: Synthese, Struktur und Derivatisierung
Author(s) -
Jutzi Peter,
Mix Andreas,
Lindermeier Tanja,
Stammler HansGeorg,
Neumann Beate
Publication year - 1994
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19941270118
Subject(s) - chemistry , pyridine , medicinal chemistry , adduct , intramolecular force , methanol , alcohol , ketone , organic chemistry , deprotonation , ion
Bis(pentamethylcyclopentadienyl)methanol: Synthesis, Structure, and Derivatization Bis(pentamethylcyclopentadienyl) ketone ( 1 ) reacts at low temperatures with LiAlH 4 to form in good yields (pentamethylcyclopentadienyl)methanol ( 2 ) and its corresponding intramolecular Diels‐Alder product 3 in a ca. 2:1 ratio. The alcohol 2 is separated from the tetracyclic compound 3 by crystallisation at −70°C from hexane/pyridine as pyridine adduct. The pyridine‐free alcohol 2 is available by repeated dissolving of the adduct in hexane and removal of the volatile components in vacuo. The alcohol tends to intramolecular [4 + 2] cycloaddition even at room temperature with formation of 3. A derivatization of 2 is possible by deprotonation with alkyllithium compounds, which leads to the alcoholate 4 , and subsequent treatment with phosgen and tosyl chloride, thus affording the chloroformate 6 and the tosylate 7 , respectively, in good yields. The thermolabile tosylate 7 decomposes to pentamethylbenzene or, under basic conditions, to the pentacyclic compound 7 .