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(9 R ,10 S )-Dihydrosterculic acid has been prepared from ( S S , S S )-1,1-bis( p -tolylsulfinyl)methane in a sequence involving an asymmetric Corey–Chaykovsky cyclopropanation and two sulfoxide/lithium exchange reactions. In most steps, the reaction conditions had to be optimized for the unbranched alkyl substituents, which were prone to Evans–Mislow rearrangements and subsequent degradation.

Semisynthetic cyclopropanoic fatty acids (CPFA), cis-9,10-methyleneheradecanoic acid, cis-7,8-methylenehexadecanoic acid, and dihydrosterculic acid, were obtained from the corresponding olefinic acids. Their chromatographic equivalent chain lengths on two liquid phases, together with the mass spectral data of the methoxy derivatives, were compared to the CPFA methoxy derivatives isolated from the lipid content of litchi seeds. The fatty acid composition of the litchi seed lipids included palmitic acid, oleic acid, linoleic acid, and CPFA

The proportions of the cyclopropenoid fatty acids (CPA) esters, malvalate and sterculate, varied little in lipids from individual cottonseeds. Coefficients of variation were 10% and 20% for seeds from a lock and 13 varieities, respectively. Within the seed, variations in CPA concentrations were very large. Cyclopropenoid fatty acid concentration in the lipids decreased from 28% in the root tip to 2% in the top of the axis, and to 0.02% in the portion of the cotyledons nearest to the hull. The axial portion was only ca. 5% of the kernel, yet it contained 75% of the CPA. Distribution of dihydrosterculic acid, the precursor of CPA, was similar to that of CPA. High concentrations of CPA were found in immature seeds, root tip and radicle of germinated seeds, and root tips of cotton plants.

The aril and seeds of the fruit Durian (Durio zibethinus, Murr.) were examined for their protein content and fatty acid composition by gas liquid chromatography (GLC). The values (area percentage) for fatty acids as methyl esters were: aril=14∶0 (0.91%); 16∶0 (34.13%); 16∶1 (7.10%); 18∶0 (1.21%); 18∶1 (42.14%); 18∶2 (7.85%) and 18∶3 plus 20∶0 (5.69%), Seeds=14∶0 (0.12%); 16∶0 (12.20%); 16∶1 (1.15%); 18∶0 (1.42%); 18∶1 (8.42%); 18∶2 (6.50%); dihydrosterculic acid (2.52%); 18∶3 plus 20∶0 (11.30%); malvalic acid (15.72%); sterculic acid (38.53%) and 22∶0 (1.21%). The germ oil contained the highest amount of sterculic acid. The cooking temperatures employed reduced the malvalic and sterculic acid contents in seeds only by ca. 22% and 19%, respectively.

Evidence is provided that sterculic and malvalic acids occur together in seed oils ofSterculia foetida, Hibiscus syriacus, andLavatera trimestris. Sterculia foetida oil contains 54.5% sterculic and 6.7% malvalic acids;Hibiscus syriacus oil contains 16.3% malvalic and 3.4% sterculic; andLavatera trimestris oil contains 7.7% malvalic and 0.6% sterculic acids.Hibiscus syriacus oil also contains 1.5% dihydrosterculic acid. The cyclopropenoid acids were characterized by hydrogenation in conjunction with gas-liquid chromatography and by oxidation to β-dioxo acids with subsequent cleavage with peracetic acid. Acetolysis of epoxides in the presence of cyclopropenes was effected by room temperature treatment with acetic acid-10% sulfuric acid (5∶2).

The total fatty acids isolated from the phospholipids of Salmonella typhimurium contained C 17 (16%) and C 19 (4%) components which were identified by gas chromatography as fatty acids with a cyclopropane-ring structure. The C 19 component was a mixture of cis -9,10-methylene octadecanoic acid (dihydrosterculic acid) and cis -11,12-methylene octadecanoic acid (lactobacillic acid). The lactobacillic acid accounted for approx. 80% of the C 19 acids.

The seed oil ofEuphoria longana, Sapindaceae, contains 17.4% of 9,10-methyleneoctadecanoic (dihydrosterculic) acid. This identification is based on information from thin layer chromatography, infrared analysis, gas liquid chromatography, nuclear magnetic resonance and mass spectroscopy. Since GLC of the oil showed components that emerged between the usual triglycerides, the cyclopropanoid acid is apparently a triglyceride constituent. The presence of smaller amounts, less than 1%, of cyclopropanoid fatty acids of different chain lengths is indicated by GLC and TLC analyses of the methyl esters. The other major fatty acids in this oil are: 16∶0 (19%), 18∶0 (7%), 18∶1 (36%), 18∶2 (6%), 18∶3 (5%) and 20∶0 (4%).Euphoria oil contains considerably larger amounts of cyclopropanoid fatty acids than previously reported in other seed oils.

The aerial parts of BLUMEA AMPLECTENS var. ARENARIA afforded taraxasteryl acetate, dihydrosterculic acid, the sesquiterpene ferutinin, and the acetylenic thiophene diol, 3,4-dihydroxy-8-[5'-methylthiophen-2'-yl]-1, 5-octadien-7-yne, named as amplectol. Thestructures were elucidated by spectroscopic methods. A biogenetic pathway for the formation of amplectol in the plant is also suggested.