During our screening of plant materials to find new natural fragrance and flavor ingredients, we discovered two series of 3-sulfanylalkyl alkanoates in a peel extract of fruits of wild-growing Poncirus trifoliata (L.) Raf. (Rutaceae), a species closely related to Citrus. The two series belong to alkanoates of 3-methyl-3-sulfanylbutan-1-ol and 3-sulfanylhexan-1-ol, respectively, and thus are members of a family of natural molecules having in common a 1,3-positioned O,S moiety. The alkanoate residues comprise all even-numbered saturated fatty acids from C2 (acetate) to C18 (octadecanoate). Among the 20 sulfur-containing compounds identified, 14 are described for the first time as naturally occurring in a botanical species. Several cysteine-S-conjugates were synthesized as hypothetical precursors of the new volatile sulfur-containing constituents, where after S-(3-hydroxy-1,1-dimethylpropyl)-L-cysteine, S-[3-(acetyloxy)-1,1-dimethylpropyl]-L-cysteine, and S-[1-(2-hydroxyethyl)butyl]-L-cysteine were identified in the fruit peel. No cysteine-S-conjugates were detected in the fruit juice.

The MHC (major histocompatibility complex) is a group of genes that play a crucial role in immune recognition and in tolerance of tissue grafting. The MHC has also been found to influence body odors, body odor preferences, and mate choice in mice and humans. Here we test whether verbal descriptions of human body odors can be linked to the MHC. We asked 45 male students to live as odor neutral as possible for two consecutive days and to wear a T-shirt during the nights. The odors of these T-shirts were then described by five evaluators: two professional perfumers and three laymen. One of the perfumers was able to describe the T-shirt odors in such a way that some of the allelic specificity of the MHC was significantly revealed (after Bonferroni correction for multiple testing). This shows that, although difficult, some people are able to describe MHC-correlated body odor components.

Ongoing interest in discovering new natural fragrance and flavor ingredients prompted us to examine a solvent extract of sulfurous-sweaty smelling Ruta chalepensis L. (Rutaceae) plant material more closely. Twenty-one sulfur-containing constituents of similar structures were identified by GC/MS techniques. Amongst them, 14 have never been described to occur in nature. The compounds 1-18 belong to a family of natural flavor and fragrance molecules having a 1,3-positioned O,S moiety in common. The identities of the natural constituents were confirmed by comparison with synthetic reference samples, and the organoleptic properties of the latter were studied. The relative and absolute configurations of the four stereoisomers of 4-methyl-3-sulfanylhexan-1-ol (5) were established by stereoselective synthesis. The natural isomers consisted of a 65 : 35 mixture of (3R,4S)-5 and (3S,4S)-5.

The peculiar and highly diffusive odorsignal of flowering clary-sage plants (Salvia sclarea L.) was identified to derive from trace amounts of 1-methoxyhexane-3-thiol (1) by mass-spectrometry analysis and confirmed by comparison with synthetic racemic thiol (+/-)-1. The enantiomers (S)- and (R)-1 were prepared by enantioselective synthesis. and the absolute configuration of (S)-I was fully corroborated by X-ray-diffraction analysis of the crystalline thioester (IS,IS)-2. Compound (S)-I is one of the most powerful odorants known, with a detection threshold of 0.04 . 10(-3) ng/l air, and is, with its herbaceous-green. alliaceous, and perspiration profile. key to the fragrance of clary-sage, flowers and of the freshly distilled essential oil. As a consequence of its unique odor. 1 was also suspected to be part of the volatiles of a Ruta species where it was subsequently pentane-3-thiol (4). identified together with its homologue, 1-Methoxvheptane-3-thiol (3), 1-methoxy-4-methyl and the known 4-methoxy-2-methylbutane-2-thiol (5). The syntheses of (+/-)-3 and (+/-)-4 as well as of the enantiomer (R)-4 are described. In both natural fractions, the ratio (S)-1(R)-1 was slightly in favor of the (S)enantiomer. Natural 4 has (R)-configuration.

The structure and synthesis of novel irregular C-12 terpenoids isolated from quince fruit (Cydonia oblonga MILL.) are described: quince oxepine (= (E)-2,3,6,7-tetrahydro-4-methyl-2-(3-methylbuta-1,3-dinyl)oxepine; 3) and the quince oxepanes as a 1:1 mixture of cis- and trans-isomers (= cis- and trans-(E)-4-methyl-2-(3-methylbuta-1,3-dienyl)oxepane; 4 and 5, resp.). The absolute configurations of the natural compounds have not been determined due to the minute amounts available, but both relative and absolute configurations of synthetic 4 and 5 were established by chemical correlation with (R)-pulegone.

Abstract(−)‐(S)‐2‐Hydroxy‐β‐ionone (33), (+)‐(2 S, 6 S)‐2‐hydroxy‐α‐ionone (34), and their acetates 35 and 36 have been synthesized from (+)‐(S)‐6‐methylbicyclo [4.3.0]‐non‐1‐ene‐3, 7‐dione (3). The key intermediate (+)‐(1 R, 3 S, 6 S)‐2, 2, 6‐trimethyl‐7‐oxobicyclo [4.3.0]non‐3‐yl acetate (7) was correlated with a degradation product of the pentacyclic triterpene ursolic acid (16). Compound 33 was also synthesized by an alternative route starting from (−)‐trans‐verbenol (42).

AbstractAus der Titel‐Spezies werden die Verbindungen (III), (IVa) + (IVb), (VIb) und (XII) isoliert, die ausgehend von (‐)‐(R)‐oc‐Phellandren (I) auf den angegebenen Wegen synthetisiert werden.

New Phellandrene Derivatives from the Root Oil of Angelica archangelica L.2‐Nitro‐1,5‐p‐menthadiene (5), trans‐ and cis‐6‐nitro‐1(7), 2‐p‐menthadiene (6 and 7), trans‐1(7), 5‐p‐menthadien‐2‐yl acetate (9) and a formal phellandrene derivative, 7‐isopropyl‐5‐methyl‐5‐bicyclo [2.2.2]octen‐2‐one (16), have been identified in the root oil of Angelica archangelica L. Starting from (−)‐(R)‐α‐phellandrene (1) (R)‐5, (4R, 6S)‐6/(4R, 6R)‐7, (2S, 4R)‐9 and (1R, 4R, 7R)‐16 as well as (2S, 4R)‐11, (2R, 4R)‐12 and (2R, 4R)‐10 have been prepared.

AbstractDas aus dem Eninol (I) erhältliche Allylchlorid (II) wird in das Thioacetal (IIIa) und dieses in den Aldehyd (IIIb) übergeführt.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA stereospecific total synthesis of racemic 11.alpha.-hydroxyprogesterone via a biomimetic polyene cyclizationWilliam S. Johnson, Sina Escher, and Brian W. MetcalfCite this: J. Am. Chem. Soc. 1976, 98, 4, 1039–1041Publication Date (Print):February 1, 1976Publication History Published online1 May 2002Published inissue 1 February 1976https://pubs.acs.org/doi/10.1021/ja00420a041https://doi.org/10.1021/ja00420a041research-articleACS PublicationsRequest reuse permissionsArticle Views323Altmetric-Citations25LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts