Synlett 2005(16): 2457-2460  
DOI: 10.1055/s-2005-917078
LETTER
© Georg Thieme Verlag Stuttgart · New York

Trimethylaluminum (TMA)-Catalyzed Reaction of Alkynyllithiums with Ethylene Oxide: Increased Yields and Purity of Homopropargylic Alcohols

Kay M. Brummond*, Jamie M. McCabe
Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
Fax: +1(412)6248611; e-Mail: kbrummon@pitt.edu; e-Mail: jmm210@pitt.edu;
Further Information

Publication History

Received 29 June 2005
Publication Date:
21 September 2005 (online)

Abstract

An efficient protocol was developed to obtain homo­propargylic alcohols. Subjecting alkynyllithiums and ethylene ­oxide to 10-20 mol% of trimethylaluminum provided homopro­pargylic alcohols in good yields.

7

Without the addition of Me3Al the yields were approximately 10% and using stoichiometric BF3·OEt2 gave 54% yield of a mixture of inseparable by-products.

12

The ethylene oxide was condensed in a separate two-neck pear shaped flask equipped with a coldfinger. Then, the ethylene oxide was removed with a plastic syringe that was pre-cooled by capping the needle with a large septa and placing it in a Ziploc bag, which was then placed in the freezer for 20 min prior to use. If larger amounts (>1 mL) of ethylene oxide were needed the desired amount was condensed into an addition funnel with a cooling jacket and added dropwise to the reaction.