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.

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.

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.

Abstract: Calanolide analogues that demonstrate potent antiviral activity against many viruses are provided. Also provided is a method of using calanolide analogues for treating or preventing viral infections. The calanolide analogues provided are obtained via syntheses employing chromene 4 and chromanone 7 as key intermediates.

Abstract: Calanolides and analogues thereof that demonstrate potent mycobacterium activity are provided. Also provided is a method of using calanolides and analogues thereof for treating or preventing mycobacterium infections. The calanolides and analogues thereof provided are obtained via syntheses employing chromene 4 and chromanone 7 as key intermediates.

Abstract: Calanolide analogues that demonstrate potent antiviral activity against many viruses are provided. Also provided is a method of using calanolide analogues for treating or preventing viral infections. The calanolide analogues provided are obtained via syntheses employing chromene 4 and chromanone 7 as key intermediates.

Abstract: An efficient and scalable method is reported for the isolation of costatolide (2), an HIV-1-specific nonnucleoside reverse transcriptase inhibitor (NNRTI), from the latex of Calophyllum plants such as C. teysmannii var. inophylloide. An overall yield of 10.6% of costatolide, with a purity of 96%, was obtained by repetitive recrystallization of the latex from a single organic solvent after the oily material was removed by treatment with hexane. A second major component of the latex, soulattrolide (3), another HIV-1 NNRTI, was also isolated. Both compounds were characterized by spectroscopic and chromatographic analyses and their in vitro anti-HIV activities were also confirmed. The results suggest that sufficient supplies of costatolide can be obtained in a relatively low-cost manner from natural sources.

Abstract: A method of preparing (.+-.)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. Useful intermediates for preparing (.+-.)-calanolide A and its derivatives are also provided. According to the disclosed method, chromene 4 intermediate was reacted with acetaldehyde diethyl acetal or paraldehyde in the presence of an acid catalyst with heating, or a two-step reaction including an aldol reaction with acetaldehyde and cyclization either under acidic conditions or neutral Mitsunobu conditions, to produce chromanone 7. Reduction of chromanone 7 with sodium borohydride, in the presence of cerium trichloride, produced (.+-.)-calanolide A. A method for resolving (.+-.)-calanolide A into its optically active forms by a chiral HPLC system or by enzymatic acylation and hydrolysis is also disclosed. Finally, a method for treating or preventing a viral infections using (.+-.)-calanolide or (-)-calanolide is provided.

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.

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.

Abstract: A method of preparing (.+-.)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. Useful intermediates for preparing (.+-.)-calanolide A and its derivatives are also provided. According to the disclosed method, chromene 4 intermediate was reacted with acetaldehyde diethyl acetal or paraldehyde in the presence of an acid catalyst with heating, or a two-step reaction including an aldol reaction with acetaldehyde and cyclization either under acidic conditions or neutral Mitsunobu conditions, to produce chromanone 7. Reduction of chromanone 7 with sodium borohydride, in the presence of cerium trichloride, produced (.+-.)-calanolide A. A method for resolving (.+-.)-calanolide A into its optically active forms by a chiral HPLC system or by enzymatic acylation and hydrolysis is also disclosed. Finally, a method for treating or preventing viral infections using (.+-.)-calanolide A or (-)-calanolide A is provided.

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.

Abstract: A method of preparing (.+-.)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. Useful intermediates for preparing (.+-.)-calanolide A and its derivatives are also provided. According to the disclosed method, chromene 4 intermediate was reacted with acetaldehyde diethyl acetal or paraldehyde in the presence of an acid catalyst with heating, or a two-step reaction including an aldol reaction with acetaldehyde and cyclization either under acidic conditions or neutral Mitsunobu conditions, to produce chromanone 7. Reduction of chromanone 7 with sodium borohydride, in the presence of cerium trichloride, produced (.+-.)-calanolide A. A method for resolving (.+-.)-calanolide A into its optically active forms by a chiral HPLC system or by enzymatic acylation and hydrolysis is also disclosed. Finally, a method for treating or preventing viral infections using (.+-.)-calanolide A or (-)-calanolide A is provided.

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.

Abstract: A method of preparing (.+-.)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. Useful intermediates for preparing (.+-.)-calanolide A and its derivatives are also provided. According to the disclosed method, chromene 4 intermediate was reacted with acetaldehyde diethyl acetal or paraldehyde in the presence of an acid catalyst with heating, or a two-step reaction including an aldol reaction with acetaldehyde and cyclization either under acidic conditions or neutral Mitsunobu conditions, to produce chromanone 7. Reduction of chromanone 7 with sodium borohydride, in the presence of cerium trichloride, produced (.+-.)-calanolide A. A method for resolving (.+-.)-calanolide A into its optically active forms by a chiral HPLC system or by enzymatic acylation and hydrolysis is also disclosed. Finally, a method for treating or preventing viral infections using (.+-.)-calanolide A or (-)-calanolide A is provided.

Abstract: A method of preparing (.+-.)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. Useful intermediates for preparing (+)-calanolide A and its derivatives are also provided. According to the disclosed method, chromene 4 intermediate was reacted with acetaldehyde diethyl acetal or paraldehyde in the presence of an acid catalyst with heating, or a two-step reaction including an aldol reaction with acetaldehyde and cyclization either under acidic conditions or neutral Mitsunobu conditions, to produce chromanone 7. Reduction of chromanone 7 with sodium borohydride, in the presence of cerium trichloride, produced (.+-.)-calanolide A. A method for resolving (.+-.)-calanolide A into its optically active forms by a chiral HPLC system or by enzymatic acylation and hydrolysis is also disclosed. Finally, a method for treating or preventing viral infections using (.+-.)-calanolide A or (-)-calanolide A is provided.