The Synthesis of a Sulfone Containing Analogue of the Esperamicin-A₁ Aglycone: A Hetero Diels-Alder Approach

The hetero Diels-Alder reaction of methyl/ethyl thioglyoxylate, generated in situ from the corresponding anthracene adduct, with a series of dienes was studied as a route to a key 3,4-dihydro-2H-thiopyran derivative bearing an acetylene function at C-2, and hydroxyl groups at C-3 and C-4. Such a molecule is a planned intermediate in the synthesis of a sulfone containing analogue of esperamicin-A₁. In this context, particular attention was directed to the hetero Diels-Alder reaction with polyfunctionalized dienes substituted at C-1 by a latent aldehyde function, and at C-4, C-2 and/or C-3 by ether substituents.

enediyne - esperamicin-A1 - 2,dihydrothia-2H-pyran - hetero Diels-Alder reaction - thioaldehyde