[74379-74-1]  · C12H18SSi  · 1-(Phenylthio)-1-(trimethylsilyl)cyclopropane  · (MW 222.46)

(Peterson alkenation;1 cyclobutane synthesis2 and cyclopentane3 annulation via 1-lithio-1-(trimethylsilyl)cyclopropane)

Physical Data: bp 64 °C/0.1 mmHg; d 0.991 g cm-3.

Form Supplied in: liquid; commercially available.

Analysis of Reagent Purity: FT-IR;1c also by NMR, IR, and mass spectrometry.1b

Preparative Methods: by reductive lithiation of 1,1-bis(phenylthio)cyclopropane followed by trimethylsilylation with Chlorotrimethylsilane.4,5

Purification: by distillation.1b

Handling, Storage, and Precautions: use in a fume hood.

Peterson Alkenation.

1-Lithio-1-(trimethylsilyl)cyclopropane, derived from 1-phenylthio-1-(trimethylsilyl)cyclopropane by reductive lithiation with Lithium 1-(Dimethylamino)naphthalenide (LDMAN), condenses with aldehydes to give carbinols which are converted to alkylidenecyclopropanes under Peterson alkenation conditions (eq 1).1

Synthesis of Cyclobutanes.

m-Chloroperbenzoic Acid oxidation of 1-phenylthio-1-(trimethylsilyl)cyclopropane furnishes a sulfoxide which could undergo thermal sila-Pummerer rearrangement to give the masked cyclopropanone 1-(phenylthio)-1-trimethylsiloxy)cyclopropane (eq 2).2a

Alternative treatment of the sulfoxide with aldehydes in the presence of Tetra-n-butylammonium Fluoride gives the phenylsulfinylcarbinol and thence the phenylthiocarbinol following reduction. The two last-named compounds are intermediates in the synthesis of cyclobutanones and cyclobutenes, respectively (eqs 3 and 4).2b,2c,2e

Cyclopentane Annulation.

Condensation of 1-lithio-1-(trimethylsilyl)cyclopropane with ketones gives vinylcyclopropane intermediates, which upon pyrolysis undergo vinylcyclopropane rearrangement to give annulated cyclopentene derivatives (eq 5).3

1. (a) Cohen, T.; Jung, S.-H.; Romberger, M. L.; McCullough, D. W. TL 1988, 29, 25. (b) Cohen, T.; Sherbine, J. P.; Matz, J. R.; Hutchins, R. R.; McHenry, B. M.; Willey, P. R. JACS 1984, 106, 3245. (c) Pouchert, C. J. Aldrich Library of FT-IR Spectra; Aldrich: Milwaukee, WI, 1989; Vol. 1, p 1669D.
2. (a) Bhupathy, M.; Cohen, T. TL 1987, 41, 4793. (b) Pohmakotr, M.; Sithikanchanakul, S. SC 1989, 19, 477. (c) Hiroi, K.; Nakamura, H.; Anzai, T. JACS 1987, 109, 1249. (d) Trost, B. M.; Keeley, D. E.; Arndt, H. C.; Rigby, J. H.; Bogdanowicz, M. J. JACS 1977, 99, 3080. (e) Trost, B. M.; Keeley, D. E.; Arndt, H. C.; Bogdanowicz, M. J. JACS 1977, 99, 3088.
3. Paquette, L. A.; Wells, G. J.; Horn, K. A.; Yan, T.-H. TL 1982, 23, 263.
4. Cohen, T.; Matz, J. R. SC 1980, 10, 311.
5. Paquette, L. A.; Horn, K. A.; Wells, G. J. TL 1982, 23, 259.

Uko E. Udodong

Eli Lilly and Company, Indianapolis, IN, USA

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