Synthesis 2002(8): 1121-1123
DOI: 10.1055/s-2002-31969
© Georg Thieme Verlag Stuttgart · New York

Reduction of Ethanethiol Esters to Aldehydes

Hidetoshi Tokuyama, Satoshi Yokoshima, Shao-Cheng Lin, Leping Li, Tohru Fukuyama*
Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
e-Mail: [email protected];
Further Information

Publication History

Received 26 March 2002
Publication Date:
03 June 2002 (online)


Reduction of ethanethiol esters of α-amino acids to α-amino aldehydes by triethylsilane and catalytic palladium-on-carbon is describ­ed. α-Amino aldehydes with Boc, Cbz, or Fmoc protection could be obtained without racemization in high yield.


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  • In Procedure 2, the optical purity of the resulting α-amino aldehyde was determined by the following procedure. An amide was obtained via a three-step sequence:
  • 3a

    NaBH4, EtOH;

  • 3b

    10% Pd/C, H2, EtOH;

  • 3c

    (R)-(+)-MTPA, DCC, MeCN]. No peak due to N-Cbz-d-phenylalaninal (δ = 3.29) was detected (Scheme [2] ).

    Scheme 2

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