ISSN:
0009-2940
Keywords:
Cyclopropanecarbothioate
;
Enolate
;
Cyclopropane, derivative
;
Clathrate
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
X-ray Crystal Structure of the Dimeric tert-Butyl 2,2-Diphenylcyclopropanecarbothioate Lithium Enolate · TMEDA Complex: an “Ordinary” Ester Enolate Containing an “Ordinary” Methylenecyclopropane MoietyAfter many unsuccessful attempts we now succeded in growing a suitable crystal of a cyclopropanecarbothioate lithium enolate (title compound 11c) for X-ray crystal structure analysis. 11c crystallizes as a tetramethylethylenediamine (TMEDA) complex in large cubes and contains hexane, is unstable above - 20°C and twinned. 11c is not C-lithiated, but exhibits features normal for an ester lithium enolate: a double bond with planar trigonal centers, a methylene cyclopropane moiety with bond lengths and angles almost identical with those in corresponding hydrocarbons, a dimeric aggregation with an almost planar Li-O-Li-O ring, with the large hydrocarbon units in a cis arrangement (Figure 1,2). A comparison with other lithiated cyclopropanes is made (Figure 3). The X-ray crystal structure analysis shows 11c to form a channel structure in which n-hexane is included. The structure described here is the first one of a thiocarboxylic acid S-ester lithium enolate.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19901231018
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