Stereoselective total synthesis of the acetylenic carotenoids alloxanthin and triophaxanthin†
Abstract
Stereoselective total synthesis of the C40-diacetylenic carotenoid alloxanthin (1) and the C31-acetylenic apocarotenoid triophaxanthin (2) was accomplished by Wittig condensation of C10-dialdehyde 20 or C16-keto aldehyde 19, respectively, with C15-acetylenic tri-n-butylphosphonium salt 12.