Patents by Inventor Sergey Dzekhster

Sergey Dzekhster 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).

  • Method for the preparation of (+)-calanolide A and analogues thereof
    Patent number: 5981770
    Abstract: A method of preparing (+)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. According to the disclosed method, chromene 4 intermediate was subjected to a chlorotitanium-mediated aldol reaction with acetaldehyde to selectively produce (.+-.)-8a. Separation and enzyme-mediated resolution of (.+-.)-8a produced (+)-8a. Cyclization of (+)-8a under neutral Mitsunobu conditions followed by Luche reduction of (+)-7 produced (+)-calanolide A in high yield and enantiomeric purity. The method of the invention has been extended to produce potent antiviral calanolide A analogues.
    Type: Grant
    Filed: September 5, 1997
    Date of Patent: November 9, 1999
    Assignee: Sarawak MediChem Pharmaceuticals, Inc.
    Inventors: Michael T. Flavin, Ze-Qi Xu, Albert Khilevich, David Zembower, John D. Rizzo, Shuyuan Liao, Aye Mar, Lin Lin, Vilayphone Vilaychack, Darko Brankovic, Sergey Dzekhster, Jinjun Liu
  • Method for the preparation of (+)-calanolide A and analogues thereof
    Patent number: 5977385
    Abstract: A method of preparing (+)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. According to the disclosed method, chromene 4 intermediate was subjected to a chlorotitanium-mediated aldol reaction with acetaldehyde to selectively produce (.+-.)-8a. Separation and enzyme-mediated resolution of (.+-.)-8a produced (+)-8a. Cyclization of (+)-8a under neutral Mitsunobu conditions followed by Luche reduction of (+)-7 produced (+)-calanolide A in high yield and enantiomeric purity. The method of the invention has been extended to produce potent antiviral calanolide A analogues.
    Type: Grant
    Filed: July 15, 1998
    Date of Patent: November 2, 1999
    Assignee: Sarawak MediChem Pharmaceuticals
    Inventors: Michael T. Flavin, Ze-Qi Xu, Albert Khilevich, David Zembower, John D. Rizzo, Shuyuan Liao, Aye Mar, Lin Lin, Vilayphone Vilaychack, Darko Brankovic, Sergey Dzekhster, Jinjun Liu
  • Method for the preparation of (+)-calanolide a and analogues thereof
    Patent number: 5892060
    Abstract: A method of preparing (+)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. According to the disclosed method, chromene 4 intermediate was subjected to a chlorotitanium-mediated aldol reaction with acetaldehyde to selectively produce (.+-.)-8a. Separation and enzyme-mediated resolution of (.+-.)-8a produced (+)-8a. Cyclization of (+)-8a under neutral Mitsunobu conditions followed by Luche reduction of (+)-7 produced (+)-calanolide A in high yield and enantiomeric purity. The method of the invention has been extended to produce potent antiviral calanolide A analogues.
    Type: Grant
    Filed: March 1, 1996
    Date of Patent: April 6, 1999
    Assignee: Sarawak MediChem Pharmaceuticals, Inc.
    Inventors: Michael T. Flavin, Ze-Qi Xu, Albert Khilevich, David Zembower, John D. Rizzo, Shuyuan Liao, Aye Mar, Lin Lin, Vilayphone Vilaychak, Darko Brankovic, Sergey Dzekhster, Jinjun Liu
  • (+)-calanolide A and analogues thereof
    Patent number: 5872264
    Abstract: A method of preparing (+)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. According to the disclosed method, chromene 4 intermediate was subjected to a chlorotitanium-mediated aldol reaction with acetaldehyde to selectively produce (.+-.)-8a. Separation and enzyme-mediated resolution of (.+-.)-8a produced (+)-8a. Cyclization of (+)-8a under neutral Mitsunobu conditions followed by Luche reduction of (.+-.)-7 produced (+)-calanolide A in high yield and enantiomeric purity. The method of the invention has been extended to produce potent antiviral calanolide A analogues.
    Type: Grant
    Filed: September 5, 1997
    Date of Patent: February 16, 1999
    Assignee: Sarawak MediChem Pharmaceuticals, Inc.
    Inventors: Michael T. Flavin, Ze-Qi Xu, Albert Khilevich, David Zembower, John D. Rizzo, Shuyuan Liao, Aye Mar, Lin Lin, Vilayphone Vilaychack, Darko Brankovic, Sergey Dzekhster, Jinjun Liu