New Regiospecific Synthesis of Tri- and Tetra-Substituted Furans
作者:Leiv K. Sydnes、Bjarte Holmelid、Myagmarsuren Sengee、Miriam Hanstein
DOI:10.1021/jo9003986
日期:2009.5.1
to react with organocuprate reagents and undergo cyclization followed by dehydration to give substituted furans as the final products. The transformation appeared to be versatile, and tri- and tetra-substituted furans were obtained with regiochemical control in moderate to good yields. The best yields were generally obtained when the reactions were performed around −60 °C with substrates and cuprates
Toward the Synthesis of Modified Carbohydrates by Conjugate Addition of Propane-1,3-dithiol to<i>α</i>,<i>β</i>-Unsaturated Ketones
作者:Stig Valdersnes、Ingrid Apeland、Guri Flemmen、Leiv K. Sydnes
DOI:10.1002/hlca.201200423
日期:2012.11
various conditions. The unprotected hydroxy ketones underwent cyclization during the dithiol addition and gave the corresponding 3‐(diethoxymethyl)‐2‐oxa‐6,10‐dithiaspiro[4.5]decan‐3‐ols 5 in 80–90% yield as the only products (Scheme 3 and Table 1). These products can be regarded as partly modified carbohydrates in the furanose form. When the benzyl‐protected analogues 10‐Bn of the 1,1‐diethoxy‐5‐hydroxypent‐3‐yn‐2‐one