The enantiospecific synthesis of (+)-monomorine I using a 5-endo- trig cyclisation strategy

• Malcolm B. Berry,
• Donald Craig,
• Philip S. Jones and
• Gareth J. Rowlands

Beilstein J. Org. Chem. 2007, 3, No. 39, doi:10.1186/1860-5397-3-39

• -cyclisation, promoted by two equivalents of potassium tert-butoxide, furnished the 2,5-syn-pyrrolidine 22 as a single diastereoisomer. Concurrently with the synthesis of 22, the isopropyl model system, 14c, was prepared using analogous chemistry. Deprotection of 22 and 14c was readily achieved with Super

The vicinal difluoro motif: The synthesis and conformation of erythro- and threo- diastereoisomers of 1,2-difluorodiphenylethanes, 2,3-difluorosuccinic acids and their derivatives

• David O'Hagan,
• Henry S. Rzepa,
• Martin Schüler and
• Alexandra M. Z. Slawin

Beilstein J. Org. Chem. 2006, 2, No. 19, doi:10.1186/1860-5397-2-19

• obtained after a dehydrobromination reaction. The elimination of hydrogen bromide from such β-fluorobromides had been explored previously, and the reaction proceeds in a stereospecific manner to generate either E or Z fluoroalkene products [20]. Accordingly treatment of 14 with potassium tert-butoxide in a

Synthesis of 2,6-trans- disubstituted 5,6-dihydropyrans from (Z)-1,5-syn-endiols

• Eric M. Flamme and
• William R. Roush

Beilstein J. Org. Chem. 2005, 1, No. 7, doi:10.1186/1860-5397-1-7

• deprotection of the TBS ether by using 3HFEt3N afforded mesylates 11 (80 – ≥ 95% yield). Treatment of mesylate 11a with 1 equivalent of potassium tert-butoxide in tert-BuOH (0.01 M) between 40–50 °C provided ent-3a in 75% yield and 10:1 selectivity for the dihydropyran product and a diene resulting from an