Tetrahedron Letters No. 37, pp 3583 - 3586. Qpergamon Press Ltd. 1979. Pribtedin GreatBritain. NEW COMPOUNDS FROM HYPTIS. X-RAY CRYSTAL AND MOLECULAR STRUCTURES OF ANAMARINE A. Alemany, C. Mbrquez, C. Pascual and S. Valverde* Instituto de Qufmica Orgdnica General, Juan de la Cierva 3, Madrid-b. Spain. M. Martinez-Ripoll, J. Fayos and A. Perales Instituto Rocasolano, Dept. de Rayos X, Serrano 119, Madrid-6. Spain. Summary. The structure (including absolute stereochemistry) of ana- marine, a new unsaturated lactone isolated from an unclassified Hyptis species, has been established. In a previous communication 1. we described the isolation of two new com- pounds - olguine and anamarine - from an unclassified Hyptis species, together with the structure elucidation of the first of these two compounds. In the present communication we report the structure of anamarine (1). Combustion analysis and mass spectrometry indicated the molecular formu- la C20H26010 for anamarine. The spectroscopic evidence suggested a close rela- tionship between olguine and anamarine SO that the same basic skeleton was assumed for both compounds. However, a comparison of the 1 H-NMR spectra of the two compounds revealed some differences. Thus, the IH-NMR spectrum of anama- rine showed the presence of four acetoxyl groups, while no signals of oxirane ring protons could be observed. (Olguine contained three acetoxyl groups and two oxirane protons.) In addition, the multiplicity of the signals of the two olefinic protons belonging to an a,B-unsaturated carbonyl function (66.07 and 6.90) suggested the presence of two protons at C-4. (Olguine had one acetoxyl group at C-4 and therefore only one proton at this centre.) Irradiation of the two H-4 protons at 62.46 confirmed their coupling to H-2 and H-3. As in the case of olguine, the lH-NMR spectrum of anamarine revealed the presence of a set-CH 3 group (61.20, J=6 Hz) and two other olefinic protons, whose signals were centred at 5.84 ppm. The signals of the remaining protons appeared be- tween 4.90 and 5.40 ppm, corresponding to the lactonic proton at C-5 and four 3583