Protolichesterinic acid ester

Another possibility is the addition of malonate anions to epoxides (equation 75), which, via the alkox-ide ester (199), deliver the lactone ester (200) immediately. This concept has been used in the non-stereocontrolled synthesis of protolichesterinic acid ester (203) from (201) via (202 equation 76). ... 

Functionalized y-acyloxy-a,yS-unsaturated esters provided yet another versatile strategy towards paraconic acids as exemplified with the synthesis of protolichesterinic acid ((-i-)-lO) (Scheme 22) [60]. The prerequisite precur-... 

Lichesterylic acid and methyl protolichesterinate have been found in Cetraria islandica (555) the latter ester was prepared from the potassium salt of protolichesterinic acid and methyl iodide 413). Allo-protolichesterinic acid adds diazomethane to form isomeric pyrazoline methylesters, the stereochemistry of which was established by their respective CD spectra. Hydrogenation of allo-protolichesterinic acid with Pd-C in acetic acid produces a mixture of (-)-dihydro-allo-protolichesterinic acid (33), (-)-nephromopsinic acid (34) and (-)-lichesterinic acid (35) (see Scheme 34). 

Potassium hydroxide, 20, 239, 303-304 Potassium persulfate, 274 Potassium superoxide, 304-307 Potassium tri-sec-butylborohydride, 307 Prins reaction, 159 Progesterone, 107 Proline, 10, 307 1,3-Propanediol, 37 Propargylic alcohols, 8, 53 Propargylic chlorides, 155 (E)-Propenyllithium, 141 Propiolaldehyde diethyl acetal, 79-80 Propiolamidium salts, 124 Fropiolate esters, 8 Propiolic add, 295 Propylene carbonate, 74 Propylene oxide, 74 Protolichesterinic add, 412 Pterocarpins, 114 Pulegone, 287, 288, 308-309 tosylhydrazones, 375-376 Pulvinic acid pigments, 291 Pumiliotoxin, 28... 

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