Facile synthesis of the cyclopentane moiety of (all-E,2R,5R,6S)-2,6-cyclolycopene-1,5-diol

The carotenoid (2R,5R,6S)-2,6-cyclolycopene-1,5-diol (1) bears a tetrasubstituted cyclopentane ring with three neighbouring stereogenic centers. The cyclic aldehyde 2 with the correct substitution pattern was synthesized in four steps from (R)-α-terpineol (3). From 2 the carotenoid 1 was prepared and investigated by CD spectroscopy.