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A new efficient enantioselective synthesis of (+)‐ cis ‐2‐methyl‐ 4‐propyl‐1,3‐oxathiane, a valuable ingredient for the aroma of passion fruit
Author(s) -
Scafato Patrizia,
Colangelo Antonella,
Rosini Carlo
Publication year - 2009
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20632
Subject(s) - chemistry , enantioselective synthesis , passion fruit , moiety , aroma , yield (engineering) , chirality (physics) , thiol , proline , stereochemistry , organic chemistry , methanethiol , sodium sulfide , catalysis , sulfur , amino acid , biochemistry , materials science , food science , chiral symmetry breaking , physics , metallurgy , quark , nambu–jona lasinio model , quantum mechanics
A new simple route to (+)‐ cis ‐2‐methyl‐4‐propyl‐1,3‐oxathiane , the main component responsible of the passion fruit aroma is shown. Such a procedure consists in the sequence of the asymmetric conjugated addition of a thiol to trans ‐2‐hexenal/cleavage of sulfide moiety, which allows to prepare, in only two steps, its immediate precursor, ( R )‐3‐mercaptohexan‐1‐ol. Various procedures have been investigated for both the steps, using benzyl and tert ‐butyl mercaptan as thiols. The best results have been achieved in the addition of benzyl thiol to trans ‐2‐hexenal mediated by a proline‐derived organocatalyst, followed by debenzylation with sodium naphthalenide, affording ( R )‐3‐mercaptohexan‐1‐ol with 84% e.e. and a yield much higher (32%) than that previously reported (8.5%). Chirality, 2009. © 2008 Wiley‐Liss, Inc.