Burnell, R. H.; Taylor, W. I. published the artcile< Ring expansion. I. Dienone-phenol rearrangement of spiro [5,5]undeca-1,4-dien-3-one>, Name: (9Z,12Z)-Methyl octadeca-9,12-dienoate, the main research area is .
Spiro[5,5]undecan-3-one (I), prepared from cyclohexanone (II) and CH2:CHCN (III) was converted into the dienone (IV), which rearranged in Ac2O-H2SO4 with simultaneous ring expansion to give 2′-acetoxybenzocydoheptene (V). III (90 g.) added during 80 min. to 10 g. Triton B in 180 g. II at 30-5° and the crude product distilled yielded unchanged II, 21 g. b1 150-90°, which was largely 2-(2-cyanoethyl)cyclohexanone, and 61 g. 2,2-bis(2-cyanoethyl)cyclohexanone (VI), m. 63°; semicarbazone, m. 196° (from EtOH). Hydrolysis of 15 g. VI by refluxing with aqueous KOH gave 16 g. 2-oxo-1,1-cyclohexanonedipropionic acid (VII), m. 136°. VII (49 g.), 20 g. KOH, and 23 cc. 85% NH2NH2 refluxed 8 hrs. in 250 cc. (CH2OH)2, the condenser removed, and the mixture heated up to 200° and maintained at that temperature 3.5 hrs. gave 39 g. 1,1-cyclohexanedipropionic acid, esterified to 44 g. of the di-Et ester (VIII), b19, 207-8°. VIII (9.7 g.) added to a suspension of 0.77 g. Na in 30 cc. PhMe at 110-15°, and the solution cooled after 5 hrs. and added to 10% aqueous HOAc yielded 4 g. Et 3-oxospiro[5,5]undecane-2-carboxylate (IX), b20 160°, λmaximum 256 mμ (log ε 3.95). IX (1.5 g.) refluxed 12 hrs. in 50% aqueous EtOH containing 2 cc. HCl yielded 0.73 g. I, b14 135-40°; 2,4-dinitrophenylhydrazone, m. 121°. I (0.7 g.) in 3 cc. HOAc decolorized 1.36 g. Br in HOAc instantly; 1 cc. HBr added and the whole left overnight gave 1.3 g. cis-dibromo spiro ketone (X), m. 132° (from Et2O). X (1.3 g.) and 3 cc. collidine boiled gently 4 min., cooled, the collidine-HCl filtered off, the filtrate taken up in Et2O, washed with dilute HCl, dried, and the resulting product chromatographed gave 250 mg. IV, m. 82°, λmaximum 235 mμ (log ε 4.2); 2,4-dinitrophenylhydrazone, m. 163-4°, λmaximum 257 and 395 mμ (log ε 4.15 and 4.44 resp.). IV (0.15 g.) in Ac2O treated with 1 drop of H2SO4 in Ac2O, kept 7 hrs., 25 cc. H2O added, and the solution set aside 12 hrs. at 0° gave 90 mg. V, m. 61-2°. Mild hydrolysis of V yielded 2′-hydroxybenzocycloheptene, m. 72° (from light petroleum). X (130 mg.) in HOAc heated 10 min. with 80 mg. 2,4-(O2N)2C6H3NHNH2 in 3 cc. HOAc gave 65 mg. of the orange 4-bromospiro[5,5]undec-1-en-3-one 2,4-dinitrophenylhydrazone, m. 157°, λmaximum 256 and 375 mμ (log ε 4.1 and 4.4 resp.). Concentration of the HOAc mother-liquors and addition of H2O furnished 43 mg. I 2,4-dinitrophenylhydrazone.
Journal of the Chemical Society published new progress about Rearrangement. 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, Name: (9Z,12Z)-Methyl octadeca-9,12-dienoate.
Referemce:
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