Syntheses and olfactory characteristics of flavouring and perfuming lactone thiono‐analogues

Thionation of several γ ‐, δ ‐ and ε ‐lactones widely used in flavours and fragrances was carried out using three different synthetic procedures. γ ‐Thionolactones were synthesized via a microwave‐assisted procedure, whereas δ ‐ and ε ‐thionolactones were prepared using Lawesson's reagent or the P 4 S 10 –HMDO combination under standard conditions. The synthesized compounds were submitted to an olfactory evaluation: γ ‐thionolactones offered a large variety of odours related to saffron, mushrooms and fruits, while δ ‐thionolactones presented a strong character of sulphur with a poor variety of olfactory notes. cis ‐Jasmone thionolactone, 6‐amylthionopyrone, and menthone thionolactone presented very interesting notes of blackcurrant, Tagetes minuta and celery, respectively. Copyright © 2005 John Wiley & Sons, Ltd.