A Short Synthesis of (+)-Bakuchiol

Tomoyuki Esumi; Chihiro Yamamoto; Yoshiyasu Fukuyama

doi:10.1055/s-0033-1338968

Synlett, Inhaltsverzeichnis

Synlett 2013; 24(14): 1845-1847
DOI: 10.1055/s-0033-1338968

letter

A Short Synthesis of (+)-Bakuchiol

Tomoyuki Esumi*

Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 7708514, Japan Fax: +81(88)6553051 eMail: esumi@ph.bunri-u.ac.jp

,

Chihiro Yamamoto

Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 7708514, Japan Fax: +81(88)6553051 eMail: esumi@ph.bunri-u.ac.jp

,

Yoshiyasu Fukuyama

Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 7708514, Japan Fax: +81(88)6553051 eMail: esumi@ph.bunri-u.ac.jp

› Institutsangaben

Abstract

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Abstract

The concise enantioselective total synthesis of (+)-bakuchiol has been achieved using an asymmetric 1,4-addition to construct its all-carbon chiral quaternary center based on the induction of chirality by the (2′S)-2′-phenyloxazolidinone auxiliary, followed by a one-pot transformation under aldol reaction conditions. The synthesis was completed in four steps from (E)-geranic acid in an overall yield of 53%.

Key words

bakuchiol - asymmetric 1,4-addition reaction - asymmetric aldol reaction - removal of oxazolidinone - decarboxylation - all-carbon quaternary center

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Referenzen

References and Notes
1 Mehta G, Nayak UR, Dev S. Tetrahedron Lett. 1966; 4561
2 Mehta G, Nayak UR, Dev S. Tetrahedron 1973; 29: 1119
3 Rao AS. C. P, Bhalla VK, NaYak UK, Dev S. Tetrahedron 1973; 29: 1127
4 Kim Y.-C, Oh H, Kim BS, Kang T.-H, Ko E.-K, Han YM, Kim BY, Ahn JS. Planta Med. 2005; 71: 87
5 Park E.-J, Zhao Y.-Z, Kim Y.-C, Sohn DH. Eur. J. Pharmacol. 2007; 559: 115
6 Haraguchi H, Inoue J, Tamura Y, Mizutani K. Planta Med. 2000; 66: 569
7 Pae LC, Sanceau J, Drapier J.-C, Wietzerbin J. Int. Immunopharmacol. 2001; 1: 1849
8 Sun NJ, Woo SH, Cassady JM, Snapka RM. J. Nat. Prod. 1998; 61: 362
9 Carnduff J, Miller JA. Chem. Commun. 1967; 606
10 Takano S, Shimazaki Y, Ogasawara K. Tetrahedron Lett. 1990; 31: 3325
11 Sakakiyama S, Yamamoto K, Asaoka M. Nat. Prod. Lett. 1999; 14: 1
12 Du X.-L, Chen H.-L, Feng H.-J, Li Y.-C. Helv. Chim. Acta 2008; 91: 371
13 Bequette JP, Jungong CS, Novikov AV. Tetrahedron Lett. 2009; 50: 6963
14 Gao F, McGrath KP, Lee Y, Hoveyda AH. J. Am. Chem. Soc. 2010; 132: 14315
15 Esumi T, Shimizu H, Kashiyama A, Sasaki C, Toyota M, Fukuyama Y. Tetrahedron Lett. 2008; 49: 6846
16 Esumi T, Yamamoto C, Tsugawa Y, Toyota M, Asakawa Y, Fukuyama Y. Org. Lett. 2013; 15: 1898
17 The ratio was determined by ¹H NMR (600 MHz).
18 Data for Synthetic (+)-Bakuchiol: [α]_D ²⁰ +26.0 (c 0.45, CHCl₃). ¹H NMR (400 MHz, CDCl₃): δ = 7.25 (d, J = 8.4 Hz, 2 H), 6.77 (d, J = 8.4 Hz, 2 H), 6.25 (d, J = 16.4 Hz, 1 H), 6.10 (d, J = 16.4 Hz, 1 H), 5.88 (dd, J = 10.8, 17.2 Hz, 1 H), 5.10 (quint t, J = 1.6, 7.2 Hz, 1 H), 5.03 (dd, J = 1.6, 10.8 Hz, 1 H), 5.01 (dd, J = 1.6, 17.2 Hz, 1 H), 4.78 (br s, 1 H), 1.95 (dt, J = 7.2, 9.2 Hz, 2 H), 1.67 (d, J = 1.2 Hz, 3 H), 1.58 (d, J = 0.8 Hz, 3 H), 1.49 (m, 2 H), 1.19 (s, 3 H). ¹³C NMR (100 MHz, CDCl₃): δ = 155.2, 146.5, 136.5, 131.9, 131.5, 127.9, 127.0, 125.4, 115.9, 112.5, 43.1, 41.9, 26.3, 23.9, 23.8, 18.2. HRMS (EI): m/z [M]⁺ calcd for C₁₈H₂₄O: 256.1821; found: 256.1827.