D. A. Evans Isoprene Building Block of Nature(3) Chem 206 From isoprene to a-pinene and bornene The Basic Process: 1-2 rearrangement DMAP geranyl pyrophosphate o Me The precursor of bornene could also lead to camphene Show the mechanism CH3 Tetrahydrocannabinol (THC) CH3 H1 chrysanthenol oliveto bornene 32A04 -terpenes312/17/99803AM- H + H + bornene -H+ ≡ 1,2 shift α−pinene ≡ -H+ limonene -H+ -OX￾isomerization geranyl pyrophosphate DMAP From isoprene to α−pinene and bornene + The Basic Process: 1-2 rearrangement + The precursor of bornene could also lead to camphene. Show the mechanism! camphene Tetrahydrocannabinol (THC) chrysanthenol olivetol aromatic substitution D. A. Evans Isoprene : Building Block of Nature (3) Chem 206 -OX OX - Me Me Me Me OX Me Me Me Me Me Me Me OX Me Me OX Me Me Me Me Me Me Me Me Me Me Me Me Me C R3 C R1 R4 CH3 R2 C R2 CH3 R C 4R1 R3 CH3 CH3 Me OH OH HO CH3 HO C5H11 OH Me Me O Me OH Me C5H11 Me C5H11 OH Me O H Me 32A-04-terpenes-3 12/17/99 8:03 AM