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3‐Hydroxy‐4‐nitro‐cyclohexanone aus Ketonen und 4‐Nitrobuttersäurechlorid. Eine ringerweiternde Fünfringanellierung
Author(s) -
Weller Thomas,
Seebach Dieter,
Davis Raymond E.,
Laird Brian B.
Publication year - 1981
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19810640314
Subject(s) - chemistry , cyclopentanone , cyclohexanone , annulation , ketone , ring (chemistry) , medicinal chemistry , tetrahydrofuran , acylation , stereochemistry , catalysis , organic chemistry , solvent
3‐Hydroxy‐4‐nitro‐cyclohexanones from Ketones and 4‐Nitrobutanoyl Chloride. A Ring Enlarging Five‐Ring Annulation The 6‐nitro‐1, 3‐diketones 5, 8, 9, 10 , and 11 , prepared by a 1:1 acylation at the C‐atom of non‐hindered lithium enolates with 4‐nitrobutanoyl chloride according to equation 3, are cyclized with sodium hydrogen carbonate in aqueous tetrahydrofuran to give the hydroxy‐nitro‐ketones 13–17 . Such cyclic nitroaldols are not formed from the cyclopentanone, ‐heptanone, and ‐octanone, nor from the aryl derivatives 4, 6, 7 and 12 , respectively. Except for the vicinally trisubstituted compound 14 , the cyclization products are isolated in diastereomerically pure form. A crystal structure X‐ray analysis reveals the trans ‐decalone and the cis β‐nitroalcohol configurations of the product 13 from cyclohexanone (see Fig. 1–3 ). Acetalization to 21–25 and catalytic hydrogenation of the nitro groups furnishes the amino alcohols 27–31 ( Table 4 ) which are substrates for the Tiffeneau‐Demjanow rearrangement (see Schemes 2, 3, 4 and 5 ), From the stereoelectronic control of this sextett rearrangement we deduce the configurations of the 1, 4‐diketones 35, 36, 39, 40, 43, 44, 46 , and 47 formed under kinetic or thermodynamic conditions. The six‐ring annulation with nitrobutanoic acid and the subsequent rearrangement are shown in Scheme 6; the sequence of reactions described here allows to carry out a ring enlargement of a cyclic ketone by one C‐atom, with simultaneous annulation of a cyclopentanone ring.