Calanolide → 5-Hydroxy-2,2-dimethyl-6-propionyl-10-propyl-2H,8H-pyrano[2,3-f]chromen-8-one

HRID 841096Notes

Reaction equation

CC1(C)OC2C3C(CCC)=CC(=O)OC=3C=C(O)C=2C=C1.[CH3:22][CH2:23][CH2:24][C:25]1[C:31]2[C:32]3[O:37][C:36]([CH3:39])([CH3:38])[CH:35]=[CH:34][C:33]=3[C:40]3[O:45][CH:44](C)[CH:43](C)[CH:42]([OH:48])[C:41]=3[C:30]=2[O:29][C:27](=[O:28])[CH:26]=1>>[CH3:39][C:36]1([CH3:38])[O:37][C:32]2[C:31]3[C:25]([CH2:24][CH2:23][CH3:22])=[CH:26][C:27](=[O:28])[O:29][C:30]=3[C:41]([C:42](=[O:48])[CH2:43][CH3:44])=[C:40]([OH:45])[C:33]=2[CH:34]=[CH:35]1

Participants

Reactant 2

HCID 1201Calanolide

HCID 5494880HCID 5494880, compound

Product 1

HCID 54948815-Hydroxy-2,2-dimethyl-6-propionyl-10-propyl-2H,8H-pyrano[2,3-f]chromen-8-one

Procedure

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.

Sources & evidence

ORD record: ord-0e3acec3b43b424fbfad1477cba5edf5
Source dataset: uspto-grants-2002_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06369241B1

Reaction notes

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