ChemInform Abstract: VITISPIRANES, IMPORTANT CONSTITUENTS OF VANILLA AROMA

Abstract

SummaryThe preparation of the vitispiranes 9 and 10, identified among the volatiles of vanilla, from the theaspiranes 1 and 2 via the intermediates 4 and 5 and the allyl alcohols 7 and 8, respectively, is described. The theaspiranes 1 and 2 can be obtained from the compounds 11-15 or 24-26.Vitispirane') (9/10), one of the most recently discovered ionone-like spiro-ethers, was identified in the volatiles of grape juice and distilled grape spirits, and in table and fortified wines [I]. We found the diastereoisomers 9 and 10 of vitispirane to be important aroma components of vanilla. Gas-chromatographic (GC.) analysis of the volatiles of a vanilla extract on a glass capillary column UCON HB 5 100 revealed the presence of the mixture 9/10 in the region between acetophenone and 5-methylfurfural. It appeared in an incompletely resolved double peak in which the ratio of 9 and 10 was about 1:32). The isomers showed practically identical mass spectra [ 11.Since it was not possible to separate 9 and 10 by preparative GC., stereoselective synthesis was undertaken. The naturally occurring theaspiranes'), a mixture of the diastereoisomeric 1 and 2 [2-41 which unlike vitispirane (9/10) can be separated by fractional distillation, were the suitable starting material. Separate treatment of cisand trans-theaspirane (1 and 2, re~pectively)~) with m-chloroperbenzoic acid yielded varying proportions of the diastereoisomeric epoxides 3 and 4, and 5 and 6, respectively, which were separated [6]. When treated with aluminium triisopropoxide at 140°, the main epoxidation products 4 and 54) gave in excellent yield exclusively the racemic allyl alcohols 7 and ti5), respectively. 7 (m.p. 70-71"), when treated with cold POCl,/pyridine, yielded cis-vitispirane (9) in over 50% yield, its diastereol) *) 3, 4, 5,For systematic names see exper. part. The NMR. spectra of the natural products show that the discoverers [l] of vitispirane also had a mixture of diastereoisomers. We thank Dr. Williams for this information and the spectra. The configuration of the theaspiranes 1 and 2 has already been established by direct linking with the known cis-and trans-theaspirone, respectively [5]. These products were also isolated from tea flavour [4] (cf. also [7]). The optically active compounds have been prepared independently in the same way [8]. We thank Drs. Kaiser and Lumparsky for the communication of the conference manuscript.

New insight on the genesis and fate of odor-active compounds in vanilla beans (Vanilla planifolia G. Jackson) during traditional curing

“…Flavor of cured vanilla beans is quite complex and over than hundred volatile compounds belonging to many chemical classes were reported (Adedeji, Hartman, & Ho, 1993;Galetto & Hoffman, 1978;Kiridena, Poole, & Poole, 1994;Klimes & Lamparsky, 1976;Nakazawa et al, 1981;Pérez-Silva et al, 2006;Ramaroson-Raonizafinimanana, Gaydou, & Bombarda, 1997;Schulte-Elte et al, 1978;Sostaric, Boyce, & Spickett, 2000;Vidal, Fort, Gaultier, & Richard, 1989;Werkhoff & Güntert, 1997). Quantitatively, vanillin is by far the major volatile in cured vanilla pod, where its concentration may reach several tens of thousands of ppm of dry matter.…”

Diastereoselektivität der Geruchswahrnehmung von Alkoholen der Iononreihe

“…IR: 1660 (CO), 1610, 1620 (C=C). 'H-NMR: 0,72-1,05 (Signalhaufen, 9H); 1,6(s,3H);1,95(d,J=6,3H);2,3(d,J=9, lH):5, 5(br.s,1H);6,08-7,32(m,4H).MS:232(9,Mt),217 (4), 162 (45), 147 (loo), 119 (13), 105 (22), 93 (29), 77 (19), 69 (55), 55 (19), 41 (37).…”

New Syntheses of Edulans and Theaspiranes from α-Ionone

“…Elution with a mixture of benzene: ethyl acetate (I : 1) gave (5) (1,26 g, 71 % yield), oil. Reduction of (5) or (6) with hydrazine (Formation of (7) or (8». i) A solution of (5) (1.26 g) in methanol (30 ml) and SO % hydrazine hydrate (1 ml) in methanol (5 ml) was stirred at O°C for 1.5 hr. The reaction mixture was extracted with ethyl acetate.…”

“…The spectral data of these tetrahydropyrans (9a and 9b) were superimposed with those of dihydroedulan I and JP) which were isolated (1), (3), (5), (7) R= H (2), q), (6). from purple passionfruit, respectively.…”