AbstractThe asymmetric Horner–Wadsworth–Emmons (HWE) reaction of the prochiral ketones 8a/b with the phosphonoacetates 10a, ent‐10a, 10b and rac‐16, which contain 8‐phenylmenthol, 8‐phenylnormenthol and trans‐2‐(triphenylsilyl)‐cyclohexanol, respectively, as chiral auxiliaries, were studied. The HWE reaction of 8a with the phosphonoenolates Li‐10a/b at low temperatures gave the esters 7a/b and 11a/b in high yields with diastereoselectivities up to 97:3. The (E)‐configured esters 7a/b serve as starting material for the total synthesis of (+)‐3‐oxacarbacyclin. Similarly, the reaction of 8b with ent‐Li‐10a gave the esters ent‐7b and ent‐11b in a ratio of 95:5 in 82% yield. The olefination of 8b with rac‐16 afforded a mixture of the esters rac‐17 and rac‐18, of yet unassigned configuration, in a ratio of 70:30. The HWE reactions of 8a/b with Li‐10a, ent‐Li‐10a and rac‐Li‐10b show linear temperature–diastereoselectivity relationships. The stereochemical course of the HWE reactions can be understood in terms of a selective addition of the chiral (E)‐configured phosphonoenolate from its least hindered side to the ketone 8 at the convex side. The asymmetric Peterson reaction of 8b with the silyl enolate Li‐20 gave the esters ent‐7b and ent‐11b in a ratio of 89:11. The diastereomerically pure β‐hydroxy esters 22, rac‐25 and 27, which contain 8‐phenyl‐menthol, trans‐2‐(triphenylsilyl)cyclohexanol and 3‐{[(3,5‐dimethylphenyl)phenylsulfonyl]amino}isoborneol, respectively, as chiral auxiliaries, were prepared by a highly selective addition of the enolates Li‐21, rac‐Li‐24 and Li‐26 to the ketone 8b. The asymmetric Martin dehydration of 22, rac‐25 and 27 with the sulfurane 23 proceeds with stereoselectivities ranging from 82:18 to 99:1. Interestingly, the HWE, Peterson and Martin reactions involving 8‐phenylmenthol as the chiral auxiliary all proceed with the same sense of asymmetric induction.