An Expeditious Enantiospecific Synthesis of (+)-2-Hydroxy-exo-brevicomin

Kavirayani R. Prasad; Pazhamalai Anbarasan

doi:10.1055/s-2006-948190

LETTER

An Expeditious Enantiospecific Synthesis of (+)-2-Hydroxy-exo-brevicomin

Kavirayani R. Prasad*, Pazhamalai Anbarasan
Department of Organic Chemistry, Indian Institute of Science, Bangalore, 560 012, India
e-Mail: prasad@orgchem.iisc.ernet.in;

Abstract

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Abstract

An expeditious approach for the synthesis of Western pine beetle pheromone 2-hydroxy-exo-brevicomin from natural chiral pool l-(+)-tartaric acid was achieved. The key step involves a highly diastereoselective reduction of a keto-Weinreb amide and further elaboration to the title compound in high yields with complete stereocontrol.

Key words

pheromone - 2-hydroxy-exo-brevicomin - tartaric acid - stereoselective reduction

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References and Notes

<A NAME="RD12006ST-1A">1a</A> Silverstein RM. Brownlee RG. Bellas TE. Wood DL. Browne LE. Science 1968, 159: 889

<A NAME="RD12006ST-1B">1b</A> Kinzer GW. Fentiman AF. Page TE. Foltz RL. Vitè JP. Pitman GB. Nature (London) 1969, 221: 477

<A NAME="RD12006ST-2">2</A> Francke W. Schröder F. Philipp P. Meyer H. Sinnwell V. Gries G. Bioorg. Med. Chem. 1996, 4: 363

<A NAME="RD12006ST-3">3</A> Mori K. Acc. Chem. Res. 2000, 33: 102

<A NAME="RD12006ST-4">4</A> Prasad KR. Anbarasan P. Tetrahedron: Asymmetry 2005, 16: 3951

<A NAME="RD12006ST-5">5</A> Prasad KR. Anbarasan P. Tetrahedron Lett. 2006, 47: 1433

<A NAME="RD12006ST-6">6</A> Prasad KR. Anbarasan P. Tetrahedron: Asymmetry 2006, 17: 850

<A NAME="RD12006ST-7A">7a</A> Yokoyama Y. Mori K. Liebigs Ann./Recl. 1997, 845

<A NAME="RD12006ST-7B">7b</A> Kumar DN. Rao BV. Tetrahedron Lett. 2004, 45: 7713

<A NAME="RD12006ST-7C">7c</A> Kumar DN. Rao BV. Tetrahedron Lett. 2004, 45: 2227

<A NAME="RD12006ST-7D">7d</A> Yokoyama Y. Mori K. Liebigs Ann./Recl. 1997, 821

<A NAME="RD12006ST-7E">7e</A> List B. Shabat D. Barbas CF. Lerner RA. Chem. Eur. J. 1998, 4: 881

<A NAME="RD12006ST-7F">7f</A> Kumar DN. Rao BV. Ramanjaneyulu GS. Tetrahedron: Asymmetry 2005, 16: 1611

<A NAME="RD12006ST-8">8</A> Nugiel DA. Jakobs K. Worley T. Patel M. Kaltenbach RF. Meyer DT. Jadhav PK. De Lucca GV. Smyser TE. Klabe RM. Bacheler LT. Rayner MM. Seitz SP. J. Med. Chem. 1996, 39: 2156

Formation of the other diastereomer was not observed within detectable limits in the ¹H NMR spectrum of the crude reaction mixture.

E-Stereochemistry for the α,β-unsaturated ketone 10 was assigned based on ¹H NMR (J = 15.9Hz). Formation of the Z isomer was not observed within detectable limits. However, stereochemistry of the olefin is irrelevant as it is saturated in the next step.

All new compounds exhibited satisfactory spectral data.
Compound 7: [α]_D ²⁵ +7.8 (c 1.6, CHCl₃). IR (neat): 2985, 2940, 1720, 1670, 1382, 1087, 993, 852 cm^-1. ¹H NMR (300 MHz, CDCl₃): δ = 4.99 (d, J = 4.5 Hz, 1 H), 4.80 (d, J = 4.5 Hz, 1 H), 3.68 (s, 3 H), 3.20 (s, 3 H), 2.80-2.48 (m, 2 H), 1.46 (s, 3 H), 1.41 (s, 3 H), 1.06 (t, J = 7.5 Hz, 3 H). ¹³C NMR (75 MHz, CDCl₃): δ = 208.8, 169.7, 112.6, 82.1, 73.9, 61.6, 32.6, 32.4, 26.6, 26.2, 7.1. HRMS: m/z calcd for C₁₁H₁₉NO₅ + Na: 268.1161; found: 268.1151.
Compound 8: [α]_D ²⁵ -7.1 (c 3.5, CHCl₃). IR (neat): 2953, 2857, 1673, 1463, 1380, 1255, 1070, 836, 777 cm^-1. ¹H NMR (300 MHz, CDCl₃): δ = 4.69 (br s, 1 H), 4.57-4.53 (m, 1 H), 3.74-3.70 (m, 1 H), 3.73 (s, 3 H), 3.19 (s, 3 H), 1.68-1.53 (m, 1 H), 1.49-1.33 (m, 1 H), 1.42 (s, 3 H), 1.41 (s, 3 H), 0.92 (t, J = 7.8 Hz, 3 H), 0.85 (s, 9 H), 0.04 (s, 6 H). ¹³C NMR (75 MHz, CDCl₃): δ = 170.5, 110.9, 79.9, 73.4, 72.4, 61.7, 32.2, 26.9, 26.2, 25.7, 25.6, 18.1, 10.2, -4.6. HRMS: m/z calcd for C₁₇H₃₅NO₅Si + Na: 384.2182; found: 384.2146.
Compound 10: [α]_D ²⁵ +11.6 (c 3, CHCl₃). IR (neat): 2931, 2857, 1681, 1471, 1369, 1253, 1089, 835, 775 cm^-1. ¹H NMR (300 MHz, CDCl₃): δ = 6.72 (dd, J = 15.9, 5.1 Hz, 1 H), 6.34 (d, J = 15.9 Hz, 1 H), 4.51 (t, J = 6.9 Hz, 1 H), 3.82-3.69 (m, 2 H), 2.26 (s, 3 H), 1.76-1.63 (m, 1 H), 1.56-1.36 (m, 1 H), 1.43 (s, 3 H), 1.39 (s, 3 H), 0.94 (t, J = 7.2 Hz, 3 H), 0.89 (s, 9 H), 0.08 (s, 3 H), 0.06 (s, 3 H). ¹³C NMR (75 MHz, CDCl₃): δ = 197.9, 143.8, 130.6, 109.5, 82.8, 75.9, 73.0, 27.4, 26.9, 26.7, 25.8, 25.6, 18.1, 10.3, -4.1, -4.6. HRMS: calcd for C₁₈H₃₄O₄Si + Na: 365.2124; found: 365.2108.
Compound 11: [α]_D ²⁵ -11.3 (c 3.1, CHCl₃). IR (neat): 2931, 2857, 1720, 1463, 1369, 1253, 1160, 1078, 836, 775 cm^-1. ¹H NMR (300 MHz, CDCl₃): δ = 3.90-3.82 (m, 1 H), 3.65-3.56 (m, 2 H), 2.74-2.50 (m, 2 H), 2.14 (s, 3 H), 2.03-1.90 (m, 1 H), 1.74-1.58 (m, 2 H), 1.47-1.36 (m, 1 H), 1.35 (s, 6 H), 0.92 (t, J = 7.2 Hz, 3 H), 0.88 (s, 9 H), 0.06 (s, 6 H). ¹³C NMR (75 MHz, CDCl₃): δ = 208.2, 135.6, 108.1, 82.8, 75.9, 73.4, 40.1, 29.9, 27.5, 27.3, 26.9, 25.9, 18.2, 10.3, -4.2, -4.6. HRMS: m/z calcd for C₁₈H₃₆O₄Si + Na: 367.2281; found: 367.2285.
2-Hydroxy-exo-brevicomin(4): [α]_D ²⁵ +32.5 (c 1.2, CHCl₃), {Lit. [7d] [α]_D ²⁵ +33.3 (c 1.94, CHCl₃)}. ¹H NMR (300 MHz, CDCl₃): δ = 4.16 (t, J = 6.6 Hz, 1 H), 3.99 (br s, 1 H), 3.97-3.88 (m, 1 H), 1.95-1.86 (m, 1 H), 1.78-1.46 (m, 5 H), 1.45 (s, 3 H), 0.93 (t, J = 7.8 Hz, 3 H). ¹³C NMR (75 MHz, CDCl₃): δ = 106.9, 80.5, 77.2, 66.2, 34.9, 28.3, 26.6, 23.8, 9.7.