Deracemization and Transacetalization of Aldehydes with Enantiomers of Betti's Base Derivatives

Abstract

Improved procedure for the deracemization of α-methyl dihydrocinnamic aldehydes (2-methyl-3-phenylpropanals) with L-(+)-tartaric acid salt of (S)-enantiomer of Betti's base, is presented. The method enabled the transacetalization of N,O-ketal (R)-enantiomer of Betti's base with various aldehydes.

GRAPHICAL ABSTRACT

Keywords:

• Aldehydes
• Betti's base
• deracemization
• tartaric acid
• transacetalization

Notes

^a Determined by HPLC on chiral stationary phase, AD-H, hexane/i-PrOH = 9:1, 1 mL/min, 254 nm, 25°C.

^a HPLC, AD-H, hexane/i-PrOH = 9:1, 1 mL/min, 254 nm, 20°C. (N,O-ketal of R-enantiomer t_R = 3.9). (AD-H, hexane/i-PrOH = 9:1, 1 mL/min, 254 nm, 20°C).

^b Based on ¹H NMR.

Note. n.a., not applicable.

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