Disclosed herein are the novel insect repellents of formula (I) to control the spread of various tropical diseases and to the process of preparation thereof wherein R, Rl, R3, R4 represents hydrogen or alkyl; R2 is selected from hydrogen, alkyl, C02R, C02H; 'n' is 1, 2, or 3; wherein any two of Rl, R2, R3 or R4 may form a 3-8 membered carbocyclic ring which may optionally be substituted or may contain a heteroatom; X is selected from O, S or CH2; ' ' represents a single or double bond; wherein, either of the ring in formula (I) may additionally contain at least one carbonyl group.
Ready Access to Functionally Embellished <i>cis</i>-Hydrindanes and <i>cis</i>-Decalins: Protecting Group-Free Total Syntheses of (±)-Nootkatone and (±)-Noreremophilane
作者:Kishor L. Handore、B. Seetharamsingh、D. Srinivasa Reddy
DOI:10.1021/jo401033j
日期:2013.8.16
A simple and efficient synthesis of functionalized cis-hydrindanes and cis-decalins was achieved using a sequential Diels-Alder/aldol approach in a highly diastereoselective manner. The scope of this method was tested with a variety of substrates and was successfully applied to the synthesis of two natural products in racemic form. The highlights of the present work provide ready access to 13 new cis-hydrindanes/cis-decalins, a protecting group-free total synthesis of an insect repellent Nootkatone, and the first synthesis of a Noreremophilane using the shortest sequence.
Stereoselective total synthesis of racemic nootkatone