text: The first total synthesis of torreyanic acid was reported by Porco an co-workers in 2000.  This total synthesis aimed to employ and confirm the Diels–Alder genesis proposed by Lee et al.  To synthesize the monomers required for Diels–Alder dimerization, 1,3-dioxane intermediate 4 was lithiated with BuLi, brominated with BrCFCFBr, and underwent acid hydrolysis to afford benzaldehyde 5.  Upon selective methylation of 5 with sulfuric acid, phenol 6 was produced in 52% yield.  Phenol 6 first underwent an allylation with allyl bromide, then a borohydride reduction, and finally a protection with a silyl group to furnish 7.  Dimethoxyacetal 8 was furnished upon thermal Claisen rearrangement of 7, which afforded an unstable allyl phenol that directly underwent a hypervalent iodine oxidation with  in methanol.  8 was then subjected to an acetal exchange with 1,3-propanediol to afford 1,3-dioxane 9, which was smoothly monoepoxidized with Ph3COOH, KHMDS, −78 °C to −20 °C over 6 hours to afford 10.  A 2-methyl-2-butenoic acid moiety was installed to afford 11.  Intermediate 11 underwent a Stille vinylation with (E)-tributyl-1-heptenyl stannane, subsequently subjected to TBAF/AcOH for silyl removal and acetal hydrolysis to afford quinone epoxide 12. Treatment of 12 with Dess-Martin periodinane initiated a tandem oxidation-6p-electrocyclization-dimerization to afford two dimeric products 13 and 14.  Upon treatment of 13 and 14 with TFA to remove the tert-butyl ester, iso-torreyanic acid 15 and torreyanic acid 1 were afforded, respectively.