Diastereoselective SmI₂-Mediated 3-exo-trig Cyclisation of δ-Oxo-Alkylidenemalonates to Cyclopropanols

Abstract

In the presence of samarium diiodide and a proton donor (tert-butanol or phenol), δ-oxo-γ,γ-disubstituted-alkylidenemalonates readily cyclise according to the 3-exo-trig mode to give, depending on the exact nature of the substrate, trans and cis cyclopropanols or lactones derived from the cis isomers. Total stereoselectivity towards the formation of trans cyclopropanols is observed with di-tert-butyl alkylidenemalonates when PhOH is used as the protonating agent.

samarium - radical reactions - cyclopropanol - cyclisations (3-exo-trig) - alkylidenemalonates

References

<A NAME="RG12605ST-1A">1a</A> David H. Bonin M. Doisneau G. Guillerez MG. Guibé F. Tetrahedron Lett.  1999,  40:  8557 

<A NAME="RG12605ST-1B">1b</A> Villar H. Guibé F. Aroulanda C. Lesot P. Tetrahedron: Asymmetry  2002,  13:  1465 

<A NAME="RG12605ST-2">2</A> Lange GA. Merica A. Tetrahedron Lett.  1999,  40:  7897 ; we became aware of this work only very recently

<A NAME="RG12605ST-3">3</A> Bezzenine-Lafollée S. Guibé F. Villar H. Zriba R. Tetrahedron  2004,  60:  6931 

<A NAME="RG12605ST-4">4</A> Inokuchi T. J. Org. Chem.  2005,  70:  1497 

<A NAME="RG12605ST-5A">5a</A> Gansäuer A. Lauterbach T. Geich-Gimbel D. Chem. Eur. J.  2004,  10:  4983 

<A NAME="RG12605ST-5B">5b</A> Friedrich J. Dolg M. Gansäuer A. Geich-Gimbel D. Lauterbach T. J. Am. Chem. Soc.  2005,  127:  7071 

<A NAME="RG12605ST-6">6</A> Fernandez-Mateos A. Mateos Buron L. Martin de la Nava EM. Rabanedo Clemente R. Rubio Gonzalez R. Sanz Gonzalez F. Synlett  2004,  2553 

<A NAME="RG12605ST-7A">7a</A> Lehnert W. Tetrahedron  1973,  29:  635 

<A NAME="RG12605ST-7B">7b</A> See also: Noguchi M. Yamada H. Takamura S. Okada K. Kakeki A. Yamamoto H. Tetrahedron  2000,  56:  1299 

<A NAME="RG12605ST-8">8</A>

Selected spectroscopic data.
Compound 9a: ¹H NMR (200 MHz, CDCl₃): δ = 3.74 (3 H, s), 3.72 (3 H, s), 2.94 (1 H, d, J = 12.0 Hz), 1.29 (3 H, s), 1.21 (3 H, s), 1.15 (1 H, d, J = 12.0 Hz), 0.93 (s, 3 H). IR (CHCl₃): 1734 cm^-1.
Compound 9d: ¹H NMR (400 MHz, CDCl₃): δ = 7.51-7.39 (5 H, m), 3.83 (3 H, s), 3.71 (3 H, s), 2.95 (1 H, d, J = 11.5 Hz), 1.64 (1 H, d, J = 11.5 Hz), 1.43 (3 H, s), 0.92 (3 H, s). IR (CHCl₃): 1734 cm^-1.
Compound 10d: ¹H NMR (250 MHz, CDCl₃): δ = 7.59-7.35 (5 H, m), 3.85 (3 H, s), 3.60 (1 H, s), 2.08 (1 H, s), 1.24 (3 H, s), 0.96 (3 H, s). IR (CHCl₃): 1781, 1739 cm^-1.

<A NAME="RG12605ST-9">9</A> Hon Y.-S. Lu L. Chu K.-P. Synth. Commun.  1991,  21:  1981 

<A NAME="RG12605ST-10A">10a</A>

This at least is the case for olefinic carbinyl radicals with k_c values [10b] [c] of 0.8 × 10⁴ s^-1 and 2.3 × 10⁵ s^-1 for cyclisations of, respectively, the parent 3-butenyl and 5-hexenyl radicals at 25 °C. Two radical processes may lead to cyclopropanols and cyclopentanols, namely the 3-exo and 5-exo cyclisations of ketyl radicals onto olefinic bond or, conversely, the 3-exo and 5-exo-cyclisations of carbinyl radicals onto carbonyl groups. Unfortunately, to the best of our knowledge only k_c value of the 5-exo-trig cyclisation of 5-oxo-pentyl radical is known. [10d]

<A NAME="RG12605ST-10B">10b</A> Newcomb M. Glenn AG. Williams GW. J. Org. Chem.  1989,  54:  2675 

<A NAME="RG12605ST-10C">10c</A> Chatgilialoglu C. Ingold KU. Scaiano JC. J. Am. Chem. Soc.  1981,  103:  7739 

<A NAME="RG12605ST-10D">10d</A> Beckwith ALJ. Hay BP. J. Am. Chem. Soc.  1989,  111:  2674 

<A NAME="RG12605ST-11">11</A> Karplus M. J. Chem. Phys.  1959,  30:  11 

<A NAME="RG12605ST-12">12</A> Barluenga J. Aznar F. Guttiérez I. Martin JA. Org. Lett.  2002,  4:  2719 

<A NAME="RG12605ST-13">13</A>

Selected spectroscopic data.
Compound 14a: ¹H NMR (400 MHz, CDCl₃): δ = 2.72 (1 H, d, J = 11.5 Hz), 1.91 (1 H, br s, OH), 1.48 and 1.47 [(9 + 9) H, 2 s], 1.31 (3 H, s), 1.25 (3 H, s), 1.08 (1 H, d, J = 11.5 Hz), 0.97 (3 H, s). IR (CHCl₃): 1721 cm^-1.
Compound 15a: ¹H NMR (400 MHz, CDCl₃): δ = 3.13 (1 H, d, J = 11.0 Hz), 1.45 and 1.44 [(9 + 9) H, 2 s], 1.40 (3 H, s), 1.06 (6 H, br s), 0.71 (1 H, d, J = 11.0 Hz). IR (CHCl₃): 1722 cm^-1.
Compound 14b: ¹H NMR (400 MHz, CDCl₃): δ = 2.78 (1 H, d, J = 12.0 Hz), 2.73 (1 H, br s, OH), 1.57-1.49 (1 H, sept, J = 8.0 Hz), 1.39 (18 H, br s), 1.18 (3 H, s), 1.11 (1 H, d, J = 12.0 Hz), 0.94 (3 H, s), 0.93 (3 H, d, J = 8.0 Hz), 0.89 (3 H, d, J = 8.0 Hz). IR (CHCl₃): 1721 cm^-1.
Compound 14c: ¹H NMR (250 MHz, CDCl₃): δ = 3.15 (1 H, br s, OH), 3.06 (1 H, d, J = 11.5 Hz), 1.78-1.63 (1 H, m), 1.52 and 1.50 [(9 + 9) H, 2 s], 1.26 (3 H, s), 1.17 (1 H, d, J = 11.5 Hz), 1.13 (3 H, s), 0.66-0.49 (2 H, m), 0.48-0.41 (1 H, m), 0.40-0.32 (1 H, m). IR (CHCl₃): 1723 cm^-1.
Compound 15c: ¹H NMR (400 MHz, CDCl₃): δ = 3.10 (1 H, d, J = 11.0 Hz), 2.32 (1 H, br s, OH), 1.44 and 1.43 [(9 + 9) H, 2 s], 1.31-1.15 (1 H, m), 1.12 (3 H, s), 1.06 (3 H, s), 0.66 (1 H, d, J = 11.0 Hz), 0.55-0.46 (2 H, m), 0.45-0.36 (1 H, m), 0.35-0.26 (1 H, m). IR (CHCl₃): 1722 cm^-1.

<A NAME="RG12605ST-14A">14a</A> Gross S. Reissig H.-U. Synlett  2002,  2027 

<A NAME="RG12605ST-14B">14b</A> Berndt M. Gross S. Hölemann A. Reissig H.-U. Synlett  2004,  422  and references cited therein

<A NAME="RG12605ST-15">15</A> Beckwith ALJ. Bowry VW. J. Am. Chem. Soc.  1994,  116:  2710 

<A NAME="RG12605ST-16">16</A> Horner JH. Tanaka N. Newcomb MW. J. Am. Chem. Soc.  1998,  120:  10379 

<A NAME="RG12605ST-17">17</A> Zytowsky T. Fischer HW. J. Am. Chem. Soc.  1996,  118:  437