NOC Approach to Spiroketals. A Total Synthesis of (+/-)-Talaromycin B

Article abstract of DOI:10.1021/ja00314a018

A total synthesis of the unqiue spiroketal natural product talaromycin B (1) is reported.This molecule, produced in nature by the toxicogenic fungus Talaromyces stipitatus, was constructed in the laboratory from the isoxazoline 6 generated (formula) on reacting the oxime 4 with the olefin 5 in the presence of NaOCl/Et3N/H20/CH2Cl2.The synthesis scheme is sufficiently flexible and efficient so as to be of practical use in the preparation of suitable quantities of this material for biological evaluation.