Synthesis reaction with organocuprates

Propiolaldehyde diethyl acetal has found numerous synthetic applications in the literature which may be briefly summarized. The compound has been utilized in the synthesis of unsaturated and polyunsaturated acetals and aldehydes by alkylation of metal-lated derivatives, " by Cadiot-Chodkiewicz coupling with halo acetylenes, " and by reaction with organocuprates. Syntheses of heterocyclic compounds including pyrazoles, isoxazoles, triazoles, and pyrimidines have employed this three-carbon building block. Propiolaldehyde diethyl acetal has also been put to use in the synthesis of such natural products as polyacetylenes " and steroids. ... 

Coupling with enol esters (7, 93). A new synthesis of an alkyl-substituted alkene involves coupling of a lithium dialkyl cuprate with an enol triflate,1 available from a ketone by reaction with triflic anhydride and 2,6-di-t-butylpyridine.2 A wide variety of organocuprates can be used and the geometry of the enolate is largely retained. Reported yields are in the range 60 100%. 

Bihovsky, R, Selick, C, Giusti, I, Synthesis of C-glucosides by reactions of glucosyl hahdes with organocuprates, J. Org. Chem., 53, 4026-4031, 1988. 

BeUosta, V, Czemecki, S, StereocontroUed synthesis of C-glycosides by reaction of organocuprates with protected 1,2-anhydro sugars, and their transformation into 2-deoxy-C-glycosides, 7. Chem. Soc., Chem. Commun., 199-200, 1989. 

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