Synthesis and Odor Evaluation of Stereoisomers of Imine Derivatives in Roasted Spotted Shrimp

Abstract

All possible stereoisomers of imine derivatives 1 ± 4, which have the characteristic roast odor of seafood, were synthesized. As a result of odor evaluation of all isomers, we found that each isomer has a different and characteristic odor of roasted seafood.Introduction. ± Imine derivatives 1 ± 4 have the characteristic roast odor of seafood.

Dinuclear Zinc‐Catalyzed Asymmetric Desymmetrization of Acyclic 2‐Substituted‐1,3‐Propanediols: A Powerful Entry into Chiral Building Blocks

“…Silica gel chromatography using ethyl acetate/hexane mixtures gave 0.27 g (74%, 88% ee) of the title compound as a white solid. The product 47 has been reported previously [29] was identified by comparison of 1 H NMR and IR data.…”

“…[29] Building block 47 proved to be a useful intermediate for the formation of nitrile 48 (path b). [29] Azide 49 (path c) can be accessed directly from the desymmetrized product 18 via a Mitsunobu reaction. [30] The desbenzoyl derivatives for both substrates 48 and 49 have been accessed from commercially available chiral 3-bromo-2-methyl-1-propanol [31] and have been employed in the total synthesis of natural products.…”

“…The absolute stereochemistry was assigned by comparison of the optical rotation of desymmetrized products 18 [5] and 47 [29] with known literature values. It was found that the (S,S)-1 ligand gives products with (S)-stereochemistry for 2-alkyl, 2-alkoxy, and 2-(hetero)aryl-1,3-propanediols.…”

Enantioselective Hydrogenation of Allylphthalimides: An Efficient Method for the Synthesis of β‐Methyl Chiral Amines

“…[2b, 10] The absolute stereochemistry of 7 a was assigned as S by comparing the sign of the optical rotation of the obtained compound 8 with the reported data [4] (see the Supporting Information). This asymmetric hydrogenation method can be applied to the preparation of the key intermediate A for the synthesis of the LTs receptor antagonist (Zeneca ZD 3532; [2] Scheme 1).…”

“…[3] To our knowledge, there has been no successful catalytic method to make such important functional groups. Although some stoichiometric asymmetric synthesis or resolution routes have been reported for constructing this class of chiral amines, [2][3][4] the development of efficient and catalytic synthetic methods remains a significant challenge. Herein we report the first highly enantioselective catalytic asymmetric hydrogenation of disubstituted allylphthalimides [5] to form chiral phthalimides, which act as precursors to the b-methyl chiral amines [Eq.…”