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Synlett 2020; 31(12): 1201-1204
DOI: 10.1055/s-0040-1707862
DOI: 10.1055/s-0040-1707862
letter
Two-Carbon Ring-Enlargement of Cyclic 1,3-Diketones to Cyclic 1,5-Diketones
This work was supported by Japan Society for the Promotion of Science (JSPS KAKENHI Grant Number 19K05473) and Kanazawa University SAKIGAKE project.Further Information
Publication History
Received: 03 April 2020
Accepted after revision: 23 April 2020
Publication Date:
29 May 2020 (online)
![](https://www.thieme-connect.de/media/synlett/202012/lookinside/thumbnails/st-2020-u0188-l_10-1055_s-0040-1707862-1.jpg)
Abstract
3-Hydroxy-3-vinylcycloalkanones, which were prepared from the corresponding cyclic 1,3-diketones by mono-vinylation, were rearranged to two-carbon ring enlarged cyclic 1,5-diketones by treatment with a catalytic amount of potassium tert-butoxide.
Key words
ring enlargement - cyclic 1,3-diketone - cyclic 1,5-diketone - mono-vinylation - potassium tert-butoxideSupporting Information
- Supporting information for this article is available online at https://doi.org/10.1055/s-0040-1707862.
- Supporting Information
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References and Notes
- 1 Cohen T, Yu LC, Daniewski WM. J. Org. Chem. 1985; 50: 4596
- 2 Wilson SR, Misra RN, Georgiadis GM. J. Org. Chem. 1980; 45: 2460
- 3 Shia K.-S, Jan N.-W, Zhu J.-L, Ly TW, Liu H.-J. Tetrahedron Lett. 1999; 40: 6753
- 4a Zhao K, Yamashita K, Carpenter JE, Sherwood TC, Ewing WR, Cheng PT. W, Knowles RR. J. Am. Chem. Soc. 2019; 141: 8752
- 4b Bulliard M, Balme G, Gore J. Tetrahedron Lett. 1989; 30: 2213
- 5a Liu Y, Yeung Y.-Y. Org. Lett. 2017; 19: 1422
- 5b Ellwood CW, Pattenden G. Tetrahedron Lett. 1991; 32: 1591
- 6 MacDougall JM, Moore HW. J. Org. Chem. 1997; 62: 4554
- 7 8-(Enol-endo-)-endo-trig intramolecular Michael addition was reported, see: Danishefsky S, Migdalof BH. Tetrahedron Lett. 1969; 4331
- 8 De Mayo reaction of cyclic 1,3-ketoesters to 1,5-ketoesters has been reported, see: Martinez-Haya R, Marzo L, Konig B. Chem. Commun. 2018; 54: 11602
- 9 Imamoto T, Takiyama N, Nakamura K. Tetrahedron Lett. 1985; 26: 4763
- 10 Krasovskiy A, Kopp F, Knochel P. Angew. Chem. Int. Ed. 2006; 45: 497
- 11 Hatano M, Ito O, Suzuki S, Ishihara K. J. Org. Chem. 2010; 75: 5008
- 12 Butler B, Schultz T, Simpkins NS. Chem. Commun. 2006; 3634
- 13 Monovinylation of linear 1,3-diketones was reported, see: Bartoli G, Marcantoni E, Petrini M. Angew. Chem., Int. Ed. Engl. 1993; 32: 1061
- 14 At this stage, the reasons for improving yields of the desired products under dilute conditions are not clear. Products formed by intermolecular reactions were not isolated in the case of undilute conditions due to the appearance of many products. In ring-enlargement of 2-monoalkyl- or 2-nonsubstituted 3-vinyl-3-hydroxycycloalkanones, basic treatment under thermodynamic conditions might form regioisomeric enolates from the intermediate 2′, and they could induce production of complex mixtures. The dilute conditions might suppress isomerization of 2′.
- 15 Potassium tert-Butoxide-Catalyzed Ring Enlargement of 3-Hydroxy-3-vinylcycloalkanones; Typical Procedure (Table [1], entry 3): To a stirred solution of 3-hydroxy-3-vinylcyclohexanone 2a (42.8 mg, 0.25 mmol) in THF (2.5 mL) was added potassium tert-butoxide (5.6 mg, 0.05 mmol) at room temperature, and the mixture was stirred at room temperature for 20 min. The reaction was quenched by adding a saturated aqueous solution of ammonium chloride. The resulting mixture was extracted with ethyl acetate (three times). The combined organic extracts were washed with brine, dried over anhydrous sodium sulfate, filtered, and concentrated. The crude product was purified by column chromatography on silica gel (hexane/ethyl acetate) to afford 3a (41.0 mg, 0.24 mmol, 96%) as colorless crystals. Compound 3a: mp 79.0–80.5 °C (recryst. from CH2Cl2), 1H NMR (CDCl3, 600 MHz): δ = 2.57–2.55 (m, 2 H), 2.51–2.49 (m, 2 H), 2.47–2.45 (m, 2 H), 2.21–2.19 (m, 2 H), 2.02–1.98 (m, 2 H), 1.12 (s, 6 H), 13C NMR (CDCl3, 150 MHz): δ = 216.0, 212.5, 47.9, 42.0, 39.7, 36.1, 32.7, 26.0, 23.5, IR (CHCl3): 1701 cm–1, HRMS (DART): m/z [M + H]+ calcd for C10H17O2: 169.12285; found: 169.12293.