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A useful methoxyvinyl cation equivalent: ?-t-butyldimethylsilyl-?-methoxyacetaldehyde.

ABSTRACT: Described are the synthesis and application of ?-t-butyldimethylsilyl-?-methoxyacetaldehyde as a formal methoxyvinyl cation equivalent. Addition of Grignard reagents to the title aldehyde, followed by treatment of the intermediate ?-hydroxysilanes with KH, gives good yields of large Z-methoxyvinylated products. Assuming a Peterson-like elimination mechanism, one can infer that the Grignard addition proceeds with high syn selectivity. These results are consistent with a chelation control model involving coordination to the ?-methoxy group in the title aldehyde rather than an alternative stereoelectronic Felkin-Anh-type model. It must be noted that a steric Felkin-Anh model also accounts for the observed stereochemistry. All told, the title reagent can be employed to efficiently append a Z-configured methoxyvinyl group to an appropriate R-M species, in two steps.

SUBMITTER: McCune CD

PROVIDER: S-EPMC4445900 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

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A useful methoxyvinyl cation equivalent: α-t-butyldimethylsilyl-α-methoxyacetaldehyde.

McCune Christopher D CD Beio Matthew L ML Friest Jacob A JA Ginotra Sandeep S Berkowitz David B DB

Tetrahedron letters 20150601 23

Described are the synthesis and application of α-t-butyldimethylsilyl-α-methoxyacetaldehyde as a formal methoxyvinyl cation equivalent. Addition of Grignard reagents to the title aldehyde, followed by treatment of the intermediate β-hydroxysilanes with KH, gives good yields of large <i>Z</i>-methoxyvinylated products. Assuming a Peterson-like elimination mechanism, one can infer that the Grignard addition proceeds with high <i>syn</i> selectivity. These results are consistent with a chelation co ...[more]

PMID: 26028786

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Dataset Information

A useful methoxyvinyl cation equivalent: ?-t-butyldimethylsilyl-?-methoxyacetaldehyde.

Publications

A useful methoxyvinyl cation equivalent: α-t-butyldimethylsilyl-α-methoxyacetaldehyde.

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