Pd-catalysed [3 + 3] annelations in the stereoselective synthesis of indolizidines

• Olivier Y. Provoost,
• Andrew J. Hazelwood and
• Joseph P. A. Harrity

Beilstein J. Org. Chem. 2007, 3, No. 8, doi:10.1186/1860-5397-3-8

• smoothly transformed to aziridine 7 after Mitsunobu condensation. Having arrived at the key [3+3] annelation step, we decided to employ our standard conditions for the Pd-catalysed reaction. Indeed, we were pleased to find that the desired piperidine 8 could be furnished in high yield and that this

Reaction of benzoxasilocines with aromatic aldehydes: Synthesis of homopterocarpans

• Míriam Álvarez-Corral,
• Cristóbal López-Sánchez,
• Leticia Jiménez-González,
• Antonio Rosales,
• Manuel Muñoz-Dorado and
• Ignacio Rodríguez-García

Beilstein J. Org. Chem. 2007, 3, No. 5, doi:10.1186/1860-5397-3-5

• with LiAlH4. Under these conditions the pivaloyl protecting group was removed, affording the dihydroxylated derivative 8. Application of the Mitsunobu conditions (DIAD, PPh3) to 9 promoted the cyclization to give the homopterocarpan 8. Therefore, following this five steps route, we have accessed the

Synthesis of coumarin or ferrocene labeled nucleosides via Staudinger ligation

• Ivana Kosiova,
• Andrea Janicova and
• Pavol Kois

Beilstein J. Org. Chem. 2006, 2, No. 23, doi:10.1186/1860-5397-2-23

• synthesised from 5'-tosylated intermediates, [36] whilst 3'-azido-3'-deoxythymidine 6 was prepared via a Mitsunobu type reaction. [37] Staudinger reaction of azidonucleosides 3–6 with triphenylphosphine led to iminophosphorane intermediates 7–10, which reacted subsequently with active esters of coumarin-4

ADDP and PS-PPh₃: an efficient Mitsunobu protocol for the preparation of pyridine ether PPAR agonists

• Paul S. Humphries,
• Quyen-Quyen T. Do and
• David M. Wilhite

Beilstein J. Org. Chem. 2006, 2, No. 21, doi:10.1186/1860-5397-2-21

• Paul S. Humphries Quyen-Quyen T. Do David M. Wilhite Pfizer Global R&D, Department of Medicinal Chemistry, 10614 Science Center Drive, San Diego, CA 92121, USA 10.1186/1860-5397-2-21 Abstract A series of pyridine ether PPAR agonists were synthesized through an ADDP and PS-PPh3 modified Mitsunobu

• (Figure 1). Aromatic ethers are structural motifs found in many naturally occurring molecules and compounds of medicinal interest.[13] We envisaged the pyridyl ether moiety of 1 to be efficiently formed via Mitsunobu coupling of the requisite pyridinol and alkyl alcohols.[14][15][16][17] Our first attempt

• at the Mitsunobu reaction between pyridinol 2 and alcohol 3, utilizing a modification of the conditions originally reported by Mitsunobu,[18] afforded pyridyl ether 4 in 54% yield (Scheme 1). Interestingly, the reaction did not reach completion and pyridinol 2 was recovered, despite the fact that it

Methods for the synthesis of polyhydroxylated piperidines by diastereoselective dihydroxylation: Exploitation in the two-directional synthesis of aza-C-linked disaccharide derivatives

• Andrew Kennedy,
• Adam Nelson and
• Alexis Perry

Beilstein J. Org. Chem. 2005, 1, No. 2, doi:10.1186/1860-5397-1-2

• and 18 were epimerised by Mitsunobu[43][44] inversion to yield the anti allylic alcohols 16 and 19. Diastereoselective dihydroxylation of a model system The diastereoselectivity of the dihydroxylation of the model compounds 15 and 17-19 was studied under both Upjohn[45] (cat. OsO4, NMO, acetone-water

• ] although the reducing agent still approaches the ketone from a pseudo-axial direction, the net stereochemical outcome is different (see Figure 6). The configuration of both alcohols in the bis-allylic alcohols trans-27 and cis-27 was cleanly inverted using a Mitsunobu reaction, and the resulting diesters