Preparation and odour properties of the four stereoisomers of 2‐hexyl‐4‐acetoxytetrahydrofuran

Abstract

The four stereoisomers of 2-hexyl-4-acetoxytetrahydrofuran were prepared starting from (R)-or (S)-1-decen-4-ol (>96% ee). They were obtained by kinetic resolution of racemic homoallylic alcohol catalysed by Novozym 435 (Candida antarctica). (R)-or (S)-1-Decen-4-ol proceeded Sharpless asymmetric dihydroxylation (AD) using AD-mix-α or β as an oxidant followed by ring closure to afford cis-2-hexyl-4-hydroxytetrahydrofuran as the major product with 50-60% de. The diastereomers were separated by derivatization to the corresponding p-nitrobenzoates, and the ee values of cis-isomers were determined by chiral HPLC to be >96%. A pair of enantiomers of cis-2-hexyl-4-hydroxytetrahydrofuran was produced by hydrolysis of the corresponding p-nitrobenzoate, respectively. The four stereoisomers of 2-hexyl-4-acetoxytetrahydrofuran were obtained with >95% ee values from (2S,4R)-or (2R,4S)-cis-2-hexyl-4-hydroxytetrahydrofuran by direct acylation with acetic anhydride or Mitsunobu reaction with acetic acid in the presence of Ph 3 P and diisopropyl azodicarboxylate. The four stereoisomers presented very distinct differences in both feature and intensity.

Synthesis and olfactory properties of Phantolide analogues in racemic and optically active forms

“…As an example, they synthesized both enantiomers of a new odorant 1 on the basis of the structure of Cashmeran, a polycyclic musk, and found that the ( R )‐enantiomer ( R )‐ 1 displayed a typical woody–musky Cashmeran odour, and the ( S )‐enantiomer ( S )‐ 1 had no musk odour (Figure ) . Enantiomers of many chemical compounds are perceived differently as odorants . Only ( R )‐ 1 was similar in odour profiles to Cashmeran in spite of the structure of 1 being different from that of Cashmeran.…”

(+)- and (−)-Petromyroxols: Antipodal Tetrahydrofurandiols from Larval Sea Lamprey (Petromyzon marinus L.) That Elicit Enantioselective Olfactory Responses

“…Many of these compounds belong to the large family known as acetogenins . Moreover, compounds with a THF–diol moiety have been shown to inhibit development and reproduction in nematodes and rats. , Compounds of this class also stimulate proliferation of human breast and prostate cancer cells. ,, Finally, the four stereoisomers of 2-hexyl-4-acetoxy­tetra­hydro­furan have recently been reported to have different odor properties and intensity …”