1. Limonoids and phytol derivatives from Cedrela sinensis
2. In the reaction of compound 1 with boron trifluoride diethyl etherate, the sole major product was 1a: The HPLC of the reaction product gave several minor peaks as well, some of which were separated and analyzed to show none was the C-21 epimer. Compound 1a, possessing an axially-oriented methoxyl group at C-21 (Fig. 4), is thermodynamically more stable than its C-21 epimer because of the anomeric effect, and thus, the C-21 epimer should be, if produced, a very minor product of the reaction.
3. Stereoelectronic Effects in Organic Chemistry;Deslongchamps,1983
4. THE STRUCTURE OF A NEW NATURAL APOTIRUCALLANE-TYPE TRITERPENE AND THE STEREOCHEMISTRY OF THE RELATED TERPENES. X-RAY AND13C NMR SPECTRAL ANALYSES