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

• Published in: Flavour and Fragrance Journal
• Main Authors: Zhang, Guoying, Gong, Xiuqin, Yang, Shaoxiang, Sun, Baoguo, Liu, Yongguo, Tian, Hongyu
• Other Authors: Financial support from the National Natural Science Foundation of China, the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions, the National Key Technology R&D Program
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1002/ffj.3202; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fffj.3202; https://onlinelibrary.wiley.com/doi/pdf/10.1002/ffj.3202

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 (2 S ,4 R )‐ or (2 R ,4 S )‐ 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. Copyright © 2014 John Wiley & Sons, Ltd.