Patents by Inventor Hua Cao

Hua Cao has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Methods for preparing antiviral calanolide compounds
    Publication number: 20020013480
    Abstract: The present invention relates to methods for preparing 2,2-dimethyl-5-acyloxy-10-propyl-2H,8H-benzo[ 1,2-b:3,4-b ′]dipyran-8-one (5) and 2,2-dimethyl-5-hydroxy- 10-propyl-2H,8H-benzo[1,2-b:3,4-b ′]dipyran-8-one (6) and their use as intermediates for the synthesis of antiviral calanolide compounds. For example, Fries rearrangement on compound 5 or Friedel-Crafts reaction on 6, yields intermediate 2,2-dimethyl-5-hydroxy-6-propionyl-10-propyl-2H,8H-benzo[1,2-b:3,4-b′]dipyran-8-one (4), which, in turn, can be converted to (+)-calanolide A and (−)-calanolide B. The coupling of compound 6 with the appropriate chiral molecule under Mitsunobu or nucleophilic displacement leads to the asymmetric synthesis of antiviral calanolide compounds.
    Type: Application
    Filed: July 31, 2001
    Publication date: January 31, 2002
    Applicant: Sarawak Medichem Pharmaceuticals, Inc.
    Inventors: Ze-Qi Xu, Hongwei Yuan, Jennifer Crabb, Raghu Samy, Ailing Li, Hua Cao