ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
p-Methyl-, p-methoxy-, and p-chlorobenzophenone condense with dimethyl homophthalate in the presence of sodium hydride to give the expected stereoisomeric half-esters 1 and 2. The (z)-configuration 2 was favoured in the two former ketones, whereas the (E)-configuration 1 prevailed in the latter. Configuration was determined by cyclisation of the derived dibasic acids 3 and 4 to the oxo-indenyl acids 7 and 8, also obtained by the action of aluminium chloride on the anhydrides 5 and 6. Cyclisation of the half-esters gave the indenyl esters 9 and 10. Structures are supported by i.r., u. v., and n. m. r. spectroscopic evidence. The ratio of isomers is interpreted in terms of the relative ease of ring cleavage of the intermediate δ-lactones 11 and 12.
Additional Material:
5 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19753170602
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