Carotenoids and Degraded Carotenoids, VIII – Synthesis of (+)‐Dihydroactinidiolide, (+)‐ and (−)‐Actinidiolide, (+)‐ and (−)‐Loliolide as well as (+)‐ and (−)‐Epiloliolide

Abstract

Abstract Enantiomerically pure ( S )‐2,4,4‐trimethyl‐2‐cyclohexen‐1‐ol ( 1 ) was efficiently converted into four degraded lactonic carotenoids: ( S )‐dihydroactinidiolide ( 5 ), ( S )‐actinidiolide ( 9 ), (6 S ,7a R )‐loliolide ( 11 ) and (6 S ,7a S )‐epiloliolide ( 12 ). ( R )‐Actinidiolide ( 9 ), (6 R ,7a S )‐loliolide ( 11 ) and (6 R ,7a R )‐epiloliolide ( 12 ) were also prepared from ( R )‐ 1 .