Photochemical transformations. Part 35. A simple synthesis of racemic terrein
Abstract
Photochemical ring contraction in the presence of sodium cyanobrohydride of 5-hydroxy-2-[(E)-prepenyl]-4-pyrone (11a), which was readily synthesised from kojic acid, gave (±)-terrein {trans-4,5-dihydroxy-3-[(E)-propenyl]cyclopent-2-enone}(1) as well as the (±)-isomer (12) with the hydroxy-groups cis.