Terpenes - XVII structure of calarene and stereochemistry of aristolone

✍ Scribed by G. Bűchi; F. Greuter; Takashi Tokoroyama

• Book ID: 104212224
• Publisher: Elsevier Science
• Year: 1962
• Tongue: French
• Weight: 326 KB
• Volume: 3
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)70529-6

✦ Synopsis

GAS chromatographic analysis of a Chinese Spikenard oil (Nardostachvs. jatamansi (Roxb.) DC., Valerianaceae) revealed the presence of at least six hydrocarbon constituents. The structures of the two major components are discussed in this communication. One of these (18 per cent) has [aIF -137' and its NMR spectrum (all in carbon tetrachloride) exhibited four methyl singlets at 8.42, 8.90, 8.98, 9.13 and a one proton multiplet at 9.25 7 with no olefinic protons. This hydrocarbon was identical in every respect with a synthetic sample of E-maaliene (l), [o]C,H"13 -135°.2 The major constituent (65 per cent) C15H24 had m.w. 204 (mass spec.); b.p. 45-47' (0.1-0.08 mm); nD 26 1.5029; [a]~ +58'; AEtoH 200, 210 (e 9560, 5480); NMR signals at 4.75 (1H broad), 9.03 (methyl doublet 56 cs), 8.92, 8.98, 9.02 (3 methyl singlets) and 9.40 T (2 cyclopropane proton multiplet). Its I.R. spectrum was superimposable3 on that of calarene, [a] lig' +18' D isolated from sweet flag (Acorus calamus L.).4 Catalytic reduction gave a saturated dihydro derivative (6), [a], cHc13 -53' identified as calarane4 by comparison of I.R. spectra. Treatment with formic acid (lOGo, 5 hr)