Catalytic asymmetric Horner-Wadsworth-Emmons reaction under phase- transfer-catalyzed conditions

Tetrahedron Letters

Volumn 39, Issue 19, 1998, Pages 2997-3000

  Arai, Shigeru ^a   Hamaguchi, Seiji ^a   Shioiri, Takayuki ^a  

^a NAGOYA CITY UNIVERSITY   (Japan)

Author keywords

Asymmetric reactions; Catalysts; Olefination; Phase transfer

Indexed keywords

DRUG; KETONE; PHOSPHONIC ACID DERIVATIVE;

ARTICLE; CATALYSIS; DRUG SYNTHESIS; PHASE TRANSITION; POLYMERIZATION;

EID: 0032493025     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(98)00442-0     Document Type: Article

References (22)

1. 1. (a) Trost, B. M.; Curran, D. P. J. Am. Chem. Soc., 1980, 102, 5699-5700.
2. (b) Hanessian, S.; Beaudoin, S. Tetrahedron Lett. 1992, 33, 7655-7658.
3. (c) Hanessian, S.; Beaudoin, S. Tetrahedron Lett. 1992, 33, 7659-7662.
4. (d) Tanaka, K.; Ohta, Y.; Fuji, K. Tetrahedron Lett. 1993, 34, 4071-4074.
5. (e) Kumamoto, T.; Koga, K. Chem. Pharm. Bull., 1997, 45, 753-755.
6. (f) Musierowioz, S.; Wroblewasi, A.; Krawczyk, H. Tetrahedron Lett. 1975, 437-440.
7. (g) Kann, N.; Rein, T. J. Org. Chem. 1993, 58, 3802-3804.
8. (h) Denmark, S. E.; Chen, C. -T. J. Am Chem. Soc. 1992, 114, 10674-10676.
9. (i) Legros, J. -Y.; Fiaud, J. -C. Tetrahedron, 1994, 50, 465-474.
10. (j) Denmark, S. E.; Rivera, I. J. Org. Chem., 1994, 59, 6887-6889 and references cited therein.
11. 2. The preparation of chiral esters via kinetic resolution was reported. See: (a) Narasaka, K.; Hidai, E.; Hayashi, Y.; Gras, J. -L. J. Chem. Soc. Chem. Commun., 1993, 102-104.
12. (b) VanNieuwenhze, M. S.; Sharpless, K. B. J. Am. Chem. Soc., 1993, 115, 7864-7865.
13. 3. The preparation of chiral esters via asymmetric elimination was reported. See: (a) Komatsu, N.; Matsunaga, S.; Sugita, T.; Uemura, S. J. Am. Chem. Soc. 1993, 115, 5847-5848.
14. (b) Solladié, G.; Zimmermann, R.; Bartsch, R. Synthesis 1985, 662-665.
15. 2, and toluene were not effective and gave the desired product with low ee.
16. 5. PTC A and C were purchased from Aldrich Chemical and Fluka Co., Ltd., respectively.
17. 6. Other substrates such as the cyano and ketophosphonate were not effective in this reaction system. Desired products were obtained in good yield with lower ee (cyanophosphonate; 72% yield, 0% ee, ketophosphonate: 78% yield, 1% ee, respectively).
18. 7. The condensation product was easily hydrolyzed under these basic conditions and obtained in low yield from the asymmetric HWE reaction. We attempted to directly convert the carboxylate to the ester with acid in alcohol. This procedure is effective to obtain the desired product in the ester form in good yield. See ref. 10.
19. 8. All PTCs except PTC A and C described here were prepared from cinchonine and a corresponding benzyl halide derivative under reflux in THF.
20. 9. According to the investigation of the base effect for the asymmetric HWE reaction, RbOH was found to give the desired product with better enantiomeric excess.
21. 10. A typical procedure for the catalytic asymmetric Homer-Wadsworth-Emmons reaction under phase-transfer-catalyzed conditions is as follows: To a solution of 4-tert-butylcyclohexanone 1 (100 mg, 0.65 mmol) in benzene (3.2 mL), triethyl phosphonoacetate 2b (0.26 mL, 1.30 mmol) and N-(4-tert-butylbenzyl)cinchoninium bromide (PTC D, 68 mg, 0.13 mmol) were added at room temperature. After RbOH monohydrate (390.6 mg, 3.2 mmol) was added at room temperature, the reaction mixture was stirred for 192 h. The reaction mixture was acidified to ca. pH=3 with conce. HCl and then ethanol (10 mL) was added, and the reaction mixture was stirred for a further 96 h at 60°C. The reaction mixture was filtered and removal of the solvent followed by column chromatography (silica gel, hexane:diethyl ether = 2:1) gave the desired product 3b as a colorless oil (109.2 mg, 75 %, 55% ee). Enantiomeric excess was determined by HPLC analysis (DAICEL CHIRALCEL OD, hexane:i-PrOH = 20:1, flow rate : 0.3 mL/min). The retention time was 13.1 min for the (R)-isomer and 14.1 min for the (S)-isomer.
22. 2 groups.