Stereoselective synthesis of (2Z,4E)-2,4-pentadien-1-ols via sequential 1,4-elimination reaction and [1,2]-Wittig rearrangement starting from (E)-4-alkoxy-2-butenyl benzoates

Takeo Nakano; Takahiro Soeta; Kohei Endo; Katsuhiko Inomata; Yutaka Ukaji

doi:10.1021/jo402272r

Stereoselective synthesis of (2Z,4E)-2,4-pentadien-1-ols via sequential 1,4-elimination reaction and [1,2]-Wittig rearrangement starting from (E)-4-alkoxy-2-butenyl benzoates

J Org Chem. 2013 Dec 20;78(24):12654-61. doi: 10.1021/jo402272r. Epub 2013 Nov 22.

Authors

Takeo Nakano¹, Takahiro Soeta, Kohei Endo, Katsuhiko Inomata, Yutaka Ukaji

Affiliation

¹ Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University , Kakuma, Kanazawa 920-1192, Japan.

PMID: 24245648
DOI: 10.1021/jo402272r

Abstract

The sequential 1,4-elimination reaction of (E)-4-alkoxy-2-butenyl benzoates and [1,2]-Wittig rearrangement gave (2Z,4E)-2,4-pentadien-1-ols stereoselectively. Z-Selective formation of intermediary vinyl ethers, whose stereochemistry was well elucidated by the "syn-effect", was achieved by treatment of the 2-butenyl benzoates with KOH in the presence of Pd catalyst. The subsequent [1,2]-Wittg rearrangement by use of n-BuLi proceeded with retention of the stereochemistry of the intermediary vinyl ethers.