High-Pressure-Promoted Uncatalyzed Cyanation of Acetals Using Trimethylsilyl Cyanide as a Cyanide Source in Nitromethane [1]

Abstract

A new uncatalyzed method for the preparation of cyanohydrin O-alkyl ethers was developed using the high-pressure-­promoted reaction of acetals with trimethylsilyl cyanide in nitro­methane.

Key words

cyanation - acetals - trimethylsilyl cyanide - nitro­methane - high pressure reaction

References and Notes

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  See also ref. 8f-h, 8o.

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10

General Procedure. A mixture of acetal (1.0 mmol) and TMSCN (1.2 mmol) in MeNO₂ (ca. 1.2 mL) was placed in a Teflon reaction vessel, and the mixture was allowed to react at 0.8 GPa at the appropriate temperature for the specified time (Table [2] ). After the mixture was cooled and the pressure was released, the mixture was concentrated in vacuo. The crude product was purified by silica gel column chromatography (elution with hexane-EtOAc) to afford the pure product in good to excellent yields.

11

Consistent with this expectation, benzaldehyde diacetyl acetal was also unreactive under similar conditions (in MeNO₂, 0.8 GPa, 80 °C, 24 h).