2010 年 58 巻 10 号 p. 1362-1365
The synthesis of 3′-deoxycapsanthin (1) and 3,4-didehydroxy-3′-deoxycapsanthin (2), carotenoids of paprika, has been achieved by employing Lewis acid-promoted regio- and stereoselective rearrangement of the C15-epoxy dienal 5a. The absolute stereochemistry of the newly formed C-5 chiral center of rearrangement product 6a was determined to be (R) from its alternative synthesis derived from (+)-(R)-camphonanic acid (11).