Novikov YY, Sampson P. 1-bromo-1-lithioethene: a practical reagent for the efficient preparation of 2-bromo-1-alken-3-ols.
Org Lett 2003;
5:2263-6. [PMID:
12816424 DOI:
10.1021/ol034594x]
[Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A reliable preparative-scale synthesis of 1-bromo-1-lithioethene is reported. This reagent undergoes clean 1,2-addition with a range of aldehydes and ketones at -105 degrees C to afford the corresponding 2-bromo-1-alken-3-ols in moderate to excellent yield. Efficient diastereoselective addition to alpha-siloxy and alpha-methylcyclohexanones, as well as protected 3-keto furanose sugars, is achieved in the presence of 10 mol % CeBr(3). The resulting bromoallylic alcohol adducts have considerable potential as synthetic building blocks. [reaction: see text]
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