A radical cyclization approach to 1α, 25-dihydroxyvitamin D₃

Synthesis of Substituted Se‐Phenyl Selenocarboxylates from Terminal Alkynes

“…The development of easy and efficient methods for the preparation of selenocarboxylic esters has attracted considerable attention because of their importance as intermediates in organic synthesis 1a−1c. In fact, among other applications, they are employed as precursors of acyl radicals,2a−2c as mild acyl transfer reagents3a−3c and as intermediates in the synthesis of ketones 4a,4b…”

Chirality Transfers through Sequential Sigmatropic Rearrangements of Allylic Vicinal Diols: Development and Application to Total Synthesis of (–)‐Kainic Acid

“…(E)-olefin 13a [13] was obtained, when the classic stable ylide was used, whereas Ando's conditions [14] led to (Z)-olefin 13b as the major product. The Wittig reaction of lactol 16 resulted in relatively lower selectivity to give 17d [17] and 17e, [18] however, trisubstituted olefin 17f was synthesized in high stereoselectivity. Enoates 13a-13c were then Scheme 3.…”

Stereo‐ and Regioselectivity in an Intramolecular Nitrone–Alkene Cycloaddition of Hept‐6‐enoses with a trans‐Acetonide Blocking Group

“…R f =0.33 (hexane/Et 2 O 4:1); [ α ]${{{20\hfill \atop {\rm D}\hfill}}}$ =−2.61 ( c =1.60 in CHCl 3 ) (ref. 26: [ α ]${{{22\hfill \atop {\rm D}\hfill}}}$ =0 ( c =0.9 in CHCl 3 )); 1 H NMR: δ =1.24 (t, J =7.2 Hz, 3 H), 1.389–1.391 (2 s, 6 H), 1.80 (dtd, J =14.4, 8.4, 6.3 Hz, 1 H), 1.95 (dddd, J =13.8, 9.3, 6.6, 3.6 Hz, 1 H), 2.34–2.55 (ddd, J =16.2, 8.7, 6.6 Hz, 1 H; ddd, J =16.2, 9.0, 6.0 Hz, 1 H), 3.69 (td, J =8.4, 3.9 Hz, 1 H), 3.99 (t, J =7.8 Hz, 1 H), 4.09–4.16 (d, J =7.2 Hz, 1 H; d, J =7.2 Hz, 1 H), 5.25 (dt, J =10.2, 0.6 Hz, 1 H), 5.37 (d, J =17.1 Hz, 1 H), 5.79 ppm (ddd, J =17.1, 10.2, 7.2 Hz, 1 H); 13 C NMR: δ =14.6, 27.2, 27.3, 27.6, 31.1, 60.8, 79.9, 82.8, 109.2, 119.6, 135.4, 173.5 ppm; IR (thin film): $\tilde \nu $ =2986, 1736, 1371, 1242, 1167, 1070, 875 cm −1 ; MS (ESI): m / z (%): 251 (100) [ M +Na] + ; HRMS (ESI): m / z calcd for C 12 H 20 O 4 [ M +Na] + : 251.1254; found: 251.1256.…”